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

[Rico Tzschichholz <ricotz src gnome org>]

commit 1d94694908ed3deeb0d6a2ed3234dcfb2ebc90ba
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Mon Nov 19 18:06:40 2018 +0100

    testrunner: Add -Werror=strict-prototypes

 configure.ac | 1 +
 1 file changed, 1 insertion(+)
---
diff --git a/configure.ac b/configure.ac
index 4b95a839a..a10cf4b19 100644
--- a/configure.ac
+++ b/configure.ac
@@ -126,6 +126,7 @@ TEST_EXTRA_CFLAGS="-Werror=init-self \
 -Werror=declaration-after-statement \
 -Werror=maybe-uninitialized \
 -Werror=missing-prototypes \
+-Werror=strict-prototypes \
 -Werror=enum-conversion"
 
 TEST_CFLAGS=