patch 9.1.1137: ins_str() is inefficient by calling STRLEN()

Problem:  ins_str() is inefficient by calling STRLLEN()
Solution: refactor ins_str() to take a length argument
          and let all callers provide the correct length
          when calling ins_str() (John Marriott)

closes: #16711

Signed-off-by: John Marriott <basilisk@internode.on.net>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 792747e..948abdf 100644
--- a/src/version.c
+++ b/src/version.c
@@ -705,6 +705,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1137,
+/**/
     1136,
 /**/
     1135,