Use a regex in installutils.get_directive instead of line splitting
This will allow for whitespace around the separator and changes the
default space separator into white space (space + tabs) to be more
generic and work better on Ubuntu which uses tabs in its Apache
configuration.
https://pagure.io/freeipa/issue/7490
Signed-off-by: Rob Crittenden <rcritten@redhat.com>
Reviewed-By: Florence Blanc-Renaud <frenaud@redhat.com>