Fixed approxhpvm.py multiple -I behavior

hpvm/tools/py-approxhpvm/main.py.in

@@ -157,7 +157,7 @@ def parse_args():
         help="File to approximation configurations; required for 'tensor' target"
     )
     parser.add_argument(
-        "-I", "--include", type=Path, nargs="+",
+        "-I", "--include", type=Path, action="append",
         help="Additional include directories to use"
     )