fix the Windows installer to install to correct directory on 64-bit OSes

wkhtmltox.nsi

@@ -3,12 +3,7 @@
 
 Name             "wkhtmltox ${VERSION}"
 OutFile          "static-build\wkhtmltox-${VERSION}_${TARGET}.exe"
-!if ${ARCH} == "win64"
 InstallDir       "$PROGRAMFILES64\wkhtmltopdf"
-!else
-InstallDir       "$PROGRAMFILES\wkhtmltopdf"
-!endif
-InstallDirRegKey HKLM "Software\wkhtmltopdf" "InstallPath"
 VIProductVersion "${SIMPLE_VERSION}.0"
 VIAddVersionKey  "ProductName"     "wkhtmltox"
 VIAddVersionKey  "FileDescription" "wkhtmltox ${VERSION}"