fix: device_credentials_install local cert check

Signed-off-by: Maximilian Deubel <[email protected]>

Author: maxd-nordic

src/nrfcloud_utils/device_credentials_installer.py

@@ -148,7 +148,7 @@ def parse_args(in_args):
                         help="For internal (Nordic) use only", default="")
     parser.add_argument("--local-cert-file", type=str,
                         help="Filepath to a local certificate (PEM) to use for the device",
-                        default="")
+                        default=None)
     parser.add_argument("--cert-type", type=int,
                         help="Certificate type to use for the device",
                         default=1)