[vala/wip/ci: 2/10] build: Ease source for AC_LANG_SOURCE of CGRAPH check

[Rico Tzschichholz <ricotz src gnome org>]

commit e5329449188720b55d211e0153aaff4f8ed34b5c
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Sun Feb 7 10:02:10 2021 +0100

    build: Ease source for AC_LANG_SOURCE of CGRAPH check

 configure.ac | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/configure.ac b/configure.ac
index 7d2c85259..66cbd52a3 100644
--- a/configure.ac
+++ b/configure.ac
@@ -180,7 +180,7 @@ if test x$enable_valadoc = xyes; then
        AC_RUN_IFELSE(
                [AC_LANG_SOURCE([
                        #include <gvc.h>
-                       int main(void) {
+                       int main() {
                                #ifdef WITH_CGRAPH
                                        return 0;
                                #else