BUG/MINOR: tcpcheck: Properly report error for http health-checks

BUG/MINOR: tcpcheck: Properly report error for http health-checks

When an error is reported on an expect rule for tcp and http health-checks,
a dedicated message is reported with details about the wrong match. However,
this was never performed for HTTP health-check because of the wrong test on
the check type.

In addition, when an error was reported on an "expect hdr" rule, a break
statement was missing. So the error message could be truncated (but never
emitted because of the issue above).

This patch should be backported to all stable versions.