patch 8.0.1258: 'ttymouse' is set to "sgr" even though it's not supported

Problem:    'ttymouse' is set to "sgr" even though it's not supported. (Gary
            Johnson)
Solution:   Adjust #ifdef
diff --git a/src/version.c b/src/version.c
index 65f5a4b..f28132c 100644
--- a/src/version.c
+++ b/src/version.c
@@ -762,6 +762,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1258,
+/**/
     1257,
 /**/
     1256,