server: fix function prototypes

Several functions in server/ were not specifying an argument list,
ie they were declared as void foo(); When compiling with
-Wstrict-prototypes, this leads to:
test_playback.c:93:5: erreur: function declaration isn’t a prototype
[-Werror=strict-prototypes]

1 files changed, 1 insertions, 1 deletions

diff --git a/server/tests/test_display_no_ssl.c b/server/tests/test_display_no_ssl.c
index b72acc9a..1eb83b37 100644
--- a/server/tests/test_display_no_ssl.c
+++ b/server/tests/test_display_no_ssl.c
@@ -35,7 +35,7 @@ int simple_commands[] = {
     SIMPLE_UPDATE,
 };
 
-int main()
+int main(void)
 {
     core = basic_event_loop_init();
     server = test_init(core);