CLEANUP: sample: Fix comment encoding of sample.c

The file contained an 'e' with an gravis accent and thus was
not US-ASCII, but ISO-8859-1.

Also correct the spelling in the incorrect comment.

The incorrect character was introduced in commit:
4d9a1d1a5c4720a169654ee47f9a4364261ffab4

v1.6-dev1 is the first tag containing this comment, the fix
should be backported to haproxy 1.6 and newer.
1 file changed