[epiphany/wip/sync] sync-service: Fix discards ‘const’ qualifier warning

[Gabriel Ivașcu <gabrielivascu src gnome org>]

commit d2d055126c8639b29b8ac8e851de4b0a7beb8785
Author: Gabriel Ivascu <ivascu gabriel59 gmail com>
Date:   Tue Mar 7 19:47:48 2017 +0200

    sync-service: Fix discards ‘const’ qualifier warning

 src/sync/ephy-sync-service.c |   13 +++++++------
 1 files changed, 7 insertions(+), 6 deletions(-)
---
diff --git a/src/sync/ephy-sync-service.c b/src/sync/ephy-sync-service.c
index 3440b20..46323bf 100644
--- a/src/sync/ephy-sync-service.c
+++ b/src/sync/ephy-sync-service.c
@@ -85,7 +85,7 @@ static guint signals[LAST_SIGNAL];
 typedef struct {
   EphySyncService     *service;
   char                *endpoint;
-  const char          *method;
+  char                *method;
   char                *request_body;
   double               modified_since;
   double               unmodified_since;
@@ -108,9 +108,9 @@ typedef struct {
 static void ephy_sync_service_send_next_storage_request (EphySyncService *self);
 
 static StorageRequestAsyncData *
-storage_server_request_async_data_new (char                *endpoint,
+storage_server_request_async_data_new (const char          *endpoint,
                                        const char          *method,
-                                       char                *request_body,
+                                       const char          *request_body,
                                        double               modified_since,
                                        double               unmodified_since,
                                        SoupSessionCallback  callback,
@@ -120,7 +120,7 @@ storage_server_request_async_data_new (char                *endpoint,
 
   data = g_slice_new (StorageRequestAsyncData);
   data->endpoint = g_strdup (endpoint);
-  data->method = method;
+  data->method = g_strdup (method);
   data->request_body = g_strdup (request_body);
   data->modified_since = modified_since;
   data->unmodified_since = unmodified_since;
@@ -136,6 +136,7 @@ storage_server_request_async_data_free (StorageRequestAsyncData *data)
   g_assert (data);
 
   g_free (data->endpoint);
+  g_free (data->method);
   g_free (data->request_body);
   g_slice_free (StorageRequestAsyncData, data);
 }
@@ -588,9 +589,9 @@ ephy_sync_service_send_next_storage_request (EphySyncService *self)
 
 static void
 ephy_sync_service_queue_storage_request (EphySyncService     *self,
-                                         char                *endpoint,
+                                         const char          *endpoint,
                                          const char          *method,
-                                         char                *request_body,
+                                         const char          *request_body,
                                          double               modified_since,
                                          double               unmodified_since,
                                          SoupSessionCallback  callback,