patch 9.1.1515: Coverity complains about potential unterminated strings

Problem:    memcpy() in ExpandRTDir_int() may create unterminated strings
Solution:   Use vim_snprintf() to construct complete paths safely
            (glepnir).

related: neovim/neovim#34795
closes: #17669

Signed-off-by: glepnir <glephunter@gmail.com>
Signed-off-by: Christian Brabandt <cb@256bit.org>
diff --git a/src/version.c b/src/version.c
index 1cf223d..f9e0bea 100644
--- a/src/version.c
+++ b/src/version.c
@@ -720,6 +720,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    1515,
+/**/
     1514,
 /**/
     1513,