Makefile.vc: fix libwebpdemux dll variable typo
Makefile.vc: fix libwebpdemux dll variable typo

Fixes issue #149

Patch by: Jason Stevens  (cypher497 at gmail dot com)

Change-Id: I65cceaad37d22b96e5e92cb78f859fc0b7c38b67
(cherry picked from commit 3eeedae1bc3be6509b6b9145f77ff4688e3820f5)

rxl194/libwebp,ttyangf/libwebp,yohunl/libwebp,PKRoma/libwebp,rxl194/libwebp,Acidburn0zzz/webm.libwebp,jiehu5114/libwebp,zofuthan/libwebp,matanbs/webm.libwebp,Acidburn0zzz/webm.libwebp,Suvarna1488/webm.libwebp,ttyangf/libwebp,matanbs/webm.libwebp,altogother/webm.libwebp,jiehu5114/libwebp,cysp/libwebp,webmproject/libwebp,jiehu5114/libwebp,kleopatra999/webm.libwebp,jacklicn/libwebp,yohunl/libwebp,yohunl/libwebp,ericmckean/webm.libwebp,redengineer/libwebp,gshORTON/webm.libwebp,iniwf/webm.libwebp,Acidburn0zzz/webm.libwebp,reimaginemedia/webm.libwebp,reimaginemedia/webm.libwebp,comoyo/gonzo-libwebp,comoyo/gonzo-libwebp,appunite/libwebp,keane83/BLE_IM,webmproject/libwebp,kalli123/webm.libwebp,abwiz0086/webm.libwebp,ericmckean/webm.libwebp,gshORTON/webm.libwebp,Aexyn/libwebp,redengineer/libwebp,webmproject/libwebp,appunite/libwebp,imazen/libwebp,comoyo/gonzo-libwebp,zofuthan/libwebp,Aexyn/libwebp,kleopatra999/webm.libwebp,kim42083/webm.libwebp,Suvarna1488/webm.libwebp,ya7lelkom/libwebp,ya7lelkom/libwebp,comoyo/gonzo-libwebp,Suvarna1488/webm.libwebp,jacklicn/libwebp,PKRoma/libwebp,abwiz0086/webm.libwebp,altogother/webm.libwebp,jiehu5114/libwebp,altogother/webm.libwebp,zofuthan/libwebp,ericmckean/webm.libwebp,Suvarna1488/webm.libwebp,ya7lelkom/libwebp,ya7lelkom/libwebp,kleopatra999/webm.libwebp,Maria1099/webm.libwebp,ya7lelkom/libwebp,abwiz0086/webm.libwebp,keane83/BLE_IM,zofuthan/libwebp,PKRoma/libwebp,appunite/libwebp,gshORTON/webm.libwebp,appunite/libwebp,rxl194/libwebp,webmproject/libwebp,Tekserve/libwebp,kim42083/webm.libwebp,jacklicn/libwebp,zofuthan/libwebp,jiehu5114/libwebp,cysp/libwebp,matanbs/webm.libwebp,keane83/BLE_IM,comoyo/gonzo-libwebp,iniwf/webm.libwebp,gshORTON/webm.libwebp,Acidburn0zzz/webm.libwebp,kleopatra999/webm.libwebp,Acidburn0zzz/webm.libwebp,Maria1099/webm.libwebp,kalli123/webm.libwebp,yohunl/libwebp,kim42083/webm.libwebp,imazen/libwebp,kalli123/webm.libwebp,yohunl/libwebp,PKRoma/libwebp,ttyangf/libwebp,Maria1099/webm.libwebp,Tekserve/libwebp,kim42083/webm.libwebp,abwiz0086/webm.libwebp,cysp/libwebp,Suvarna1488/webm.libwebp,iniwf/webm.libwebp,Maria1099/webm.libwebp,ericmckean/webm.libwebp,cysp/libwebp,kim42083/webm.libwebp,kalli123/webm.libwebp,keane83/BLE_IM,rxl194/libwebp,abwiz0086/webm.libwebp,appunite/libwebp,redengineer/libwebp,imazen/libwebp,Tekserve/libwebp,rxl194/libwebp,reimaginemedia/webm.libwebp,PKRoma/libwebp,altogother/webm.libwebp,redengineer/libwebp,webmproject/libwebp,gshORTON/webm.libwebp,appunite/libwebp,imazen/libwebp,imazen/libwebp,reimaginemedia/webm.libwebp,jacklicn/libwebp,kleopatra999/webm.libwebp,Aexyn/libwebp,ttyangf/libwebp,iniwf/webm.libwebp,Maria1099/webm.libwebp,matanbs/webm.libwebp,ericmckean/webm.libwebp,ttyangf/libwebp,iniwf/webm.libwebp,matanbs/webm.libwebp,altogother/webm.libwebp,redengineer/libwebp,Aexyn/libwebp,Tekserve/libwebp,comoyo/gonzo-libwebp,jacklicn/libwebp,reimaginemedia/webm.libwebp,keane83/BLE_IM,Aexyn/libwebp,kalli123/webm.libwebp,comoyo/gonzo-libwebp,PKRoma/libwebp