fix nmake build

Author: jtsiomb

.github/workflows/build_win_msvc6.yml

@@ -40,7 +40,7 @@ jobs:
       shell: cmd
       run: |
         call vc6fullvarsgh.bat
-        nmake -f Makefile.msvc
+        nmake -f Makefile.vc
         copy game.exe isorpg-win32-msvc
 
     - uses: actions/upload-artifact@v4

Makefile.vc

@@ -26,7 +26,7 @@ clean:
 
 libs\w32\imago.lib:
 	cd libs\imago
-	$(MAKE) /nologo -f Makefile.msvc
+	$(MAKE) /nologo -f Makefile.vc
 	cd ..\..
 
 # vi:ft=make: