jira/client.py: Map IssueLinkType array to string array

Equality check between IssueLinkType and string always returns false.
Function decorator casts IssueLinkType parameters to string, so a
warning is always logged. This fixes that issue.

Closes: pycontribs#1875
Signed-off-by: Shymon Samsel <shymon.samsel@raytheon.com>

jira/client.py

@@ -2929,7 +2929,7 @@ def create_issue_link(
             Response
         """
         # let's see if we have the right issue link 'type' and fix it if needed
-        issue_link_types = self.issue_link_types()
+        issue_link_types = list(map(lambda x: x.name, self.issue_link_types()))
 
         if type not in issue_link_types:
             self.log.warning(