Makefile: libcaca configure does detect mingw properly under cygwin, give it a hand

extras/contrib/src/Makefile

@@ -1082,7 +1082,11 @@ libcaca: libcaca-$(LIBCACA_VERSION).tar.gz
 	$(EXTRACT_GZ)
 
 .caca: libcaca
+ifdef HAVE_WIN32
+	(cd $<; $(HOSTCC) ./configure $(HOSTCONF) --prefix=$(PREFIX) --enable-win32 --disable-x11 --disable-imlib2 --disable-doc && make && make install)
+else
 	(cd $<; $(HOSTCC) ./configure $(HOSTCONF) --prefix=$(PREFIX) --disable-imlib2 --disable-doc && make && make install)
+endif
 	touch $@
 
 CLEAN_FILE += .caca