[Panelize][Fixed] not able to use external JSON configs

Fixes #592

CHANGELOG.md

@@ -20,6 +20,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - BoardView: X axis mirroring issues (whitequark/kicad-boardview#11)
 - Present: problems when using gerbers already generated
 - Diff: problems when using things like "origin/main" and add_link_id (#589)
+- Panelize: not able to use external JSON configs (#592)
 
 ## [1.6.4] - 2024-02-02
 ### Added

kibot/out_panelize.py

@@ -658,6 +658,8 @@ class PanelizeOptions(VariantOptions):
         elif isinstance(self.configs, str):
             self.configs = [self.configs]
         for c, cfg in enumerate(self.configs):
+            if isinstance(cfg, str):
+                continue
             if not cfg.name:
                 cfg.name = str(c+1)