fixed docs error, should be issue_pat

docs/setup.rst

@@ -451,11 +451,11 b' to define a regular expression that will'
 messages and replace that with an url to this issue. To enable this simply
 uncomment following variables in the ini file::
 
-    url_pat = (?:^#|\s#)(\w+)
+    issue_pat = (?:^#|\s#)(\w+)
     issue_server_link = https://myissueserver.com/{repo}/issue/{id}
     issue_prefix = #
 
-`url_pat` is the regular expression that will fetch issues from commit messages.
+`issue_pat` is the regular expression that will fetch issues from commit messages.
 Default regex will match issues in format of #<number> eg. #300.
 
 Matched issues will be replace with the link specified as `issue_server_link`