[gnome-sdk-images] Gstreamer: Use the correct plugin path

[Jordan Petridis <jpetridis src gnome org>]

commit e081cd0cd96be6f4b2bf7792c08a621937624a18
Author: Jordan Petridis <jpetridis gnome org>
Date:   Sat Sep 15 16:09:40 2018 +0300

    Gstreamer: Use the correct plugin path
    
    The /extensions/  path is not multiarch in the Freedesktop-SDK.
    
    
https://gitlab.com/freedesktop-sdk/freedesktop-sdk/blob/20fe02c0ce7ea9547ccbcb49febc037224a0342e/elements/flatpak-images/sdk.bst#L18

 org.gnome.Sdk.json.in | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/org.gnome.Sdk.json.in b/org.gnome.Sdk.json.in
index b74040f..bed32e1 100644
--- a/org.gnome.Sdk.json.in
+++ b/org.gnome.Sdk.json.in
@@ -30,7 +30,7 @@
     },
     "finish-args": [
         "--env=GI_TYPELIB_PATH=/app/lib/girepository-1.0",
-        "--env=GST_PLUGIN_PATH=/app/lib/gstreamer-1.0:/usr/@@SDK_LIB@@/extensions/gstreamer-1.0",
+        "--env=GST_PLUGIN_PATH=/app/lib/gstreamer-1.0:/usr/lib/extensions/gstreamer-1.0",
         "--env=XDG_DATA_DIRS=/app/share:/usr/share:/usr/share/runtime/share:/run/host/share",
         "--sdk=org.gnome.Sdk//@@SDK_BRANCH@@",
         "--runtime=org.gnome.Platform//@@SDK_BRANCH@@"