Merge branch 'version-string-develop' into 'master'

Add DEVELOP build flag to version string

See merge request STJr/SRB2!401

src/d_netcmd.c

@@ -3465,6 +3465,11 @@ static void Command_Version_f(void)
 	CONS_Printf("\x85" "DEBUG " "\x80");
 #endif
 
+	// DEVELOP build
+#ifdef DEVELOP
+	CONS_Printf("\x87" "DEVELOP " "\x80");
+#endif
+
 	CONS_Printf("\n");
 }