patch 8.1.0115: the matchparen plugin may throw an error

Problem:    The matchparen plugin may throw an error.
Solution:   Change the skip argument from zero to "0".
diff --git a/runtime/plugin/matchparen.vim b/runtime/plugin/matchparen.vim
index 4f68fd8..0fa5c4d 100644
--- a/runtime/plugin/matchparen.vim
+++ b/runtime/plugin/matchparen.vim
@@ -114,7 +114,7 @@
   " within those syntax types (i.e., not skip).  Otherwise, the cursor is
   " outside of the syntax types and s_skip should keep its value so we skip any
   " matching pair inside the syntax types.
-  execute 'if' s_skip '| let s_skip = 0 | endif'
+  execute 'if' s_skip '| let s_skip = "0" | endif'
 
   " Limit the search to lines visible in the window.
   let stoplinebottom = line('w$')
diff --git a/src/version.c b/src/version.c
index 076778a..fa4ec60 100644
--- a/src/version.c
+++ b/src/version.c
@@ -790,6 +790,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    115,
+/**/
     114,
 /**/
     113,