LaTeXFeatures.cpp: fix bug #9266 also for branch

mhchem loads amsmath and needs therefore be loaded after it but before packages that redefine commands of amsmath. We already take care of esint but not of wasysym
Merge remote-tracking branch 'github/build-bot-2.1.x' into bleeding-edge-2.1.x
2014.10.26-13.00