panel search crash due to strescape.h include missing from screen.c (ticket #2044)

> In current git, mc crashes (at least on 64-bit) in Ctrl-S search due to missing
> strutils_escape prototype. To reproduce, pressing Ctrl-S and a few keys is enough.
> Adding #include "lib/strescape.h" to screen.c fixes the issue.

Reported by jmak

Signed-off-by: Sergei Trofimovich <slyfox@inbox.ru>

src/screen.c

@@ -35,6 +35,7 @@
 
 #include "lib/tty/tty.h"
 #include "lib/skin.h"
+#include "lib/strescape.h"
 #include "lib/tty/mouse.h"		/* For Gpm_Event */
 #include "lib/tty/key.h"		/* XCTRL and ALT macros  */
 #include "lib/filehighlight.h"