Incorrect truncations of long links

[doc-sheet]

Hi! I found same issue as #1080 but it happens in link text, not in issue description.

Text could be truncated in the middle of character leading to �... trailings.

I don't see if truncate is used for links

mattermost-plugin-jira/server/issue_parser.go

Line 83 in fe02ece

text := mdKeySummaryLink(issue, instance)

So I made separate issue report.