Catch potential user error

- if passed to 'available', this creates a long and not very helpful message
  that lists all branches.
- if we catch it here, we avoid that.

mpsd-software.py

@@ -1113,6 +1113,14 @@ def main():
         get_installer_log_file_path(args.release, args.action, root_dir),
     )
 
+    # sanity check for common mistakes in command line arguments
+    if args.release.endswith("/"):  # happens easily with autocompletion
+        logging.error(
+            f"You provided mpsd-release='{args.release}'. "
+            "Did you mean '{args.release.rstrip('/')}'?"
+        )
+        sys.exit(1)
+
     # Check the command and run related function
     if args.action == "remove":
         remove_environment(args.release, args.toolchains, root_dir)