cmake: fixed method to locate arch-specific python libraries (patch be Bruno Postle)
cmake: fixed method to locate arch-specific python libraries (patch be Bruno Postle)

xiwei-zhang/vigra,martinsch/vigra,funkey/vigra,cbecker/vigra,kod3r/vigra,mmuellner/vigra,xiwei-zhang/vigra,mmuellner/vigra,kod3r/vigra,hmeine/vigra,timoMa/vigra,DaveRichmond-/vigra,hmeine/vigra,funkey/vigra,martinsch/vigra,timoMa/vigra,stuarteberg/vigra,funkey/vigra,funkey/vigra,cha007/vigra,psteinb/vigra,mmuellner/vigra,funkey/vigra,cbecker/vigra,hmeine/vigra,ThomasWalter/vigra,dagophil/vigra,martinsch/vigra,xiwei-zhang/vigra,mmuellner/vigra,timoMa/vigra,cha007/vigra,DaveRichmond-/vigra,mmuellner/vigra,dstoe/vigra,stuarteberg/vigra,capturePointer/vigra,psteinb/vigra,psteinb/vigra,dstoe/vigra,cha007/vigra,cha007/vigra,cbecker/vigra,DaveRichmond-/vigra,cbecker/vigra,ThomasWalter/vigra,funkey/vigra,stuarteberg/vigra,cbecker/vigra,dstoe/vigra,timoMa/vigra,dagophil/vigra,xiwei-zhang/vigra,psteinb/vigra,mmuellner/vigra,hmeine/vigra,xiwei-zhang/vigra,capturePointer/vigra,cha007/vigra,kod3r/vigra,stuarteberg/vigra,kod3r/vigra,dagophil/vigra,hmeine/vigra,cha007/vigra,ThomasWalter/vigra,ThomasWalter/vigra,hmeine/vigra,xiwei-zhang/vigra,psteinb/vigra,ThomasWalter/vigra,dagophil/vigra,cha007/vigra,dagophil/vigra,dagophil/vigra,dstoe/vigra,martinsch/vigra,capturePointer/vigra,ThomasWalter/vigra,martinsch/vigra,mmuellner/vigra,dstoe/vigra,xiwei-zhang/vigra,DaveRichmond-/vigra,dstoe/vigra,stuarteberg/vigra,martinsch/vigra,kod3r/vigra,dstoe/vigra,DaveRichmond-/vigra,timoMa/vigra,capturePointer/vigra,ThomasWalter/vigra,stuarteberg/vigra,DaveRichmond-/vigra,capturePointer/vigra,timoMa/vigra,kod3r/vigra,cbecker/vigra,DaveRichmond-/vigra,kod3r/vigra,psteinb/vigra,stuarteberg/vigra,funkey/vigra,dagophil/vigra,capturePointer/vigra,psteinb/vigra,capturePointer/vigra,hmeine/vigra,timoMa/vigra