BUG/MINOR: reg-tests: fix service dependency script

BUG/MINOR: reg-tests: fix service dependency script

I badly tested my previous patch forgetting to remove the "+" testing
present in options, and not in services; the list of services do not
have any "+" at the beginning of each service

this patch is fixing commit aabde7133242563109b4f36c42e732f083 ("MINOR:
reg-tests: add a way to add service dependency")

Signed-off-by: William Dauchy <wdauchy@gmail.com>
(cherry picked from commit 4488434c97b4ae3ae8fde501b37f5ef9a588bd09)
Signed-off-by: Christopher Faulet <cfaulet@haproxy.com>