Remove unnecessary check

A bit convoluted check that cannot fail, since everything now relies on
var.sh being imported, which is guarranteed to set $MKIT_LOCAL to a
non-empty value.

src/include/mkit.sh

     MKIT_PROJ_PKGNAME=$(ini 1value "project:pkgname")
     test -f "$MKIT_INI" || die "cannot find mkit.ini: $MKIT_INI"
     _chkiniversion
-    test -n "$(tr -d '[:space:]' <<<"$MKIT_LOCAL")" \
-     || die "MKIT_LOCAL must be non-blank: '$MKIT_LOCAL'"
 }
 
 route() {