FIXED: Incorrect use of findstring Makefile function (NSIS for Win64)
FIXED: Incorrect use of findstring Makefile function (NSIS for Win64)

jn7163/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,koryonik/swipl-devel,edechter/swipl-devel,koryonik/swipl-devel,koryonik/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,koryonik/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,koryonik/swipl-devel,mndrix/swipl-devel,edechter/swipl-devel,edechter/swipl-devel,jn7163/swipl-devel,jn7163/swipl-devel,mndrix/swipl-devel,mndrix/swipl-devel