?action=credits target
?action=credits target

- The ?action=credits link no longer opens in a new window since it's
internal.
- Concatenation tweak.

Signed-Off: Matthew "Labradoodle-360" Kerle <6d6f1c82e106df665d8ea00563f1880103db4f36@simplemachines.org>

mkress/SMF2.1,MustafaCan/SMF2.1,margarett/SMF2.1,StealthWombat/SMF2.1-more-forkery,mkress/SMF2.1,margarett/SMF2.1,georaldc/SMF2.1,MustafaCan/SMF2.1,georaldc/SMF2.1,StealthWombat/SMF2.1-more-forkery,mkress/SMF2.1