[pygobject] Disable -Werror=missing-prototypes

[Christoph Reiter <creiter src gnome org>]

commit d005df9645fd5fb2f19bd09384355f45591f1e58
Author: Christoph Reiter <creiter src gnome org>
Date:   Mon Jan 23 21:26:05 2017 +0100

    Disable -Werror=missing-prototypes
    
    https://bugzilla.gnome.org/show_bug.cgi?id=760056
    added some code triggering "missing-prototype" which we by default
    treat as an error. This disables that specific error by default.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=777534

 configure.ac |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)
---
diff --git a/configure.ac b/configure.ac
index c8d95c7..8e225f4 100644
--- a/configure.ac
+++ b/configure.ac
@@ -228,7 +228,7 @@ AC_SUBST(INTROSPECTION_SCANNER)
 AC_SUBST(INTROSPECTION_COMPILER)
 
 # compiler warnings, errors, required cflags, and code coverage support
-GNOME_COMPILE_WARNINGS([maximum])
+GNOME_COMPILE_WARNINGS([maximum], [-Wno-error=missing-prototypes])
 AC_MSG_CHECKING(for Gnome code coverage support)
 m4_ifdef([GNOME_CODE_COVERAGE],
          [AC_MSG_RESULT(yes)