patch 7.4.1256

Problem:    On Mac sys.exit(0) doesn't kill the test server.
Solution:   Use self.server.shutdown(). (Jun Takimoto)

src/version.c

@@ -742,6 +742,8 @@ static char *(features[]) =
 
 static int included_patches[] =
 {   /* Add new patch number below this line */
+/**/
+    1256,
 /**/
     1255,
 /**/