[vala/staging] testrunner: Add -Werror=missing-prototypes

[Rico Tzschichholz <ricotz src gnome org>]

commit 538bfd9f628ab5a35556394b08b7df54da683562
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Mon Nov 5 08:29:45 2018 +0100

    testrunner: Add -Werror=missing-prototypes

 configure.ac | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/configure.ac b/configure.ac
index 6496a7fbf..4b95a839a 100644
--- a/configure.ac
+++ b/configure.ac
@@ -125,6 +125,7 @@ TEST_EXTRA_CFLAGS="-Werror=init-self \
 -Werror=duplicated-cond \
 -Werror=declaration-after-statement \
 -Werror=maybe-uninitialized \
+-Werror=missing-prototypes \
 -Werror=enum-conversion"
 
 TEST_CFLAGS=