net/echoping: unbreak final .else path

eugen@ revived this museum piece but it's broken with default options;
the excess backslash I am removing with this commit hides the .else path
in the IDN2/IDN switch.

However, it is not a good idea to keep undead software in the tree though,
and this shows as broken on a poudriere build w/ 14.2-RELEASE amd64.

Reported by: diizzy@
Approved by: portmgr@ (blanket just-fix-it approval)