[zendframework/zf2#2146] Minor cleanup
[zendframework/zf2#2146] Minor cleanup

- Re-add parts of exception messages that were removed
- Remove unnecessary else blocks

zf2timo/zend-inputfilter,akrabat/zend-inputfilter,akomm/zend-inputfilter,zendframework/zend-inputfilter,MadCat34/zend-inputfilter,Blinden/zend-inputfilter,stefanotorresi/zend-inputfilter,Maks3w/zend-inputfilter,weierophinney/zend-inputfilter