[Bugfix] Delete commas when escaping tag content

[mattwd7]

Addresses issue #300

#294 introduced a change wherein commas (,) are no longer deleted from tags unless that tag includes a pipe char (|). This causes tags containing commas to report differently than before the change, resulting in data misalignment.

This change will delete commas (again) if they are included in the tag string.

[rayz]

Thanks @mattwd7 ! I'll make a new release with this fix.

[jasonpenny]

@rayz I installed the new release 5.6.4, but looking at the code with bundle open dogstatsd-ruby I still see the old code (before this fix)?