core: increase buffer size in function plugin_api_info_uptime_cb

This fixes a compiler warning complaining about a too small buffer for
snprintf, even if this should never happen.

src/plugins/plugin-api-info.c

@@ -723,7 +723,7 @@ plugin_api_info_uptime_cb (const void *pointer, void *data,
                            const char *info_name,
                            const char *arguments)
 {
-    char value[32];
+    char value[128];
     time_t total_seconds;
     int days, hours, minutes, seconds;