fix missing WebPInitAlphaProcessing call for premultiplied colorspace output
fix missing WebPInitAlphaProcessing call for premultiplied colorspace output

(lossless only)

Change-Id: Ic2d01c8cf9bc1082f07f348733461eb2ee30288a

ya7lelkom/libwebp,Maria1099/webm.libwebp,PKRoma/libwebp,jiehu5114/libwebp,ericmckean/webm.libwebp,comoyo/gonzo-libwebp,jacklicn/libwebp,matanbs/webm.libwebp,comoyo/gonzo-libwebp,appunite/libwebp,PKRoma/libwebp,ericmckean/webm.libwebp,matanbs/webm.libwebp,webmproject/libwebp,Aexyn/libwebp,gshORTON/webm.libwebp,Acidburn0zzz/webm.libwebp,webmproject/libwebp,abwiz0086/webm.libwebp,altogother/webm.libwebp,rxl194/libwebp,kalli123/webm.libwebp,ya7lelkom/libwebp,reimaginemedia/webm.libwebp,jacklicn/libwebp,ya7lelkom/libwebp,Aexyn/libwebp,redengineer/libwebp,reimaginemedia/webm.libwebp,iniwf/webm.libwebp,redengineer/libwebp,comoyo/gonzo-libwebp,ttyangf/libwebp,gshORTON/webm.libwebp,ttyangf/libwebp,iniwf/webm.libwebp,yohunl/libwebp,jacklicn/libwebp,redengineer/libwebp,comoyo/gonzo-libwebp,PKRoma/libwebp,yohunl/libwebp,appunite/libwebp,jiehu5114/libwebp,kalli123/webm.libwebp,jacklicn/libwebp,appunite/libwebp,Maria1099/webm.libwebp,appunite/libwebp,redengineer/libwebp,kalli123/webm.libwebp,reimaginemedia/webm.libwebp,iniwf/webm.libwebp,zofuthan/libwebp,Aexyn/libwebp,gshORTON/webm.libwebp,zofuthan/libwebp,yohunl/libwebp,imazen/libwebp,yohunl/libwebp,kleopatra999/webm.libwebp,Acidburn0zzz/webm.libwebp,abwiz0086/webm.libwebp,redengineer/libwebp,jiehu5114/libwebp,Acidburn0zzz/webm.libwebp,ericmckean/webm.libwebp,kim42083/webm.libwebp,imazen/libwebp,altogother/webm.libwebp,kalli123/webm.libwebp,rxl194/libwebp,Aexyn/libwebp,reimaginemedia/webm.libwebp,ericmckean/webm.libwebp,rxl194/libwebp,kim42083/webm.libwebp,rxl194/libwebp,jiehu5114/libwebp,Aexyn/libwebp,ttyangf/libwebp,webmproject/libwebp,ya7lelkom/libwebp,iniwf/webm.libwebp,jacklicn/libwebp,ttyangf/libwebp,PKRoma/libwebp,comoyo/gonzo-libwebp,Maria1099/webm.libwebp,ya7lelkom/libwebp,zofuthan/libwebp,ttyangf/libwebp,kleopatra999/webm.libwebp,ericmckean/webm.libwebp,rxl194/libwebp,altogother/webm.libwebp,yohunl/libwebp,PKRoma/libwebp,kim42083/webm.libwebp,comoyo/gonzo-libwebp,abwiz0086/webm.libwebp,reimaginemedia/webm.libwebp,matanbs/webm.libwebp,appunite/libwebp,imazen/libwebp,comoyo/gonzo-libwebp,kalli123/webm.libwebp,Suvarna1488/webm.libwebp,kleopatra999/webm.libwebp,kleopatra999/webm.libwebp,PKRoma/libwebp,gshORTON/webm.libwebp,altogother/webm.libwebp,kim42083/webm.libwebp,appunite/libwebp,imazen/libwebp,gshORTON/webm.libwebp,abwiz0086/webm.libwebp,iniwf/webm.libwebp,altogother/webm.libwebp,zofuthan/libwebp,Suvarna1488/webm.libwebp,kim42083/webm.libwebp,abwiz0086/webm.libwebp,zofuthan/libwebp,Suvarna1488/webm.libwebp,Suvarna1488/webm.libwebp,Maria1099/webm.libwebp,Suvarna1488/webm.libwebp,Acidburn0zzz/webm.libwebp,kleopatra999/webm.libwebp,Maria1099/webm.libwebp,matanbs/webm.libwebp,webmproject/libwebp,matanbs/webm.libwebp,webmproject/libwebp,jiehu5114/libwebp,Acidburn0zzz/webm.libwebp,imazen/libwebp