Fix extra quotes in firewall string matching

Fix extra quotes in firewall string matching

As reported by Steve Traylon[1] and @patricknelson[2], the munging adds extra quotes to the string.
This breaks the string matching in iptables, as it looks for literal single quotes in the match.

Removing the munging fixes this.

[1] https://tickets.puppetlabs.com/browse/MODULES-3454?focusedCommentId=686988&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-686988
[2] https://github.com/puppetlabs/puppetlabs-firewall/commit/3655c6bd33d662a3813c2f66cd0bc5889c68c2c2#diff-379160b60a9bdf297b92a51d20efd8c3R1426