Merge pull request #1696 from nanograv/dlakaplan-patch-1

Fix observatory.__init__.py

src/pint/observatory/__init__.py

@@ -152,7 +152,7 @@ def __new__(cls, name, *args, **kwargs):
         if name.lower() in cls._registry:
             if "overwrite" not in kwargs or not kwargs["overwrite"]:
                 raise ValueError(
-                    f"Observatory {name.lower} already present and overwrite=False"
+                    f"Observatory {name.lower()} already present and overwrite=False"
                 )
             log.warning(f"Observatory '{name.lower()}' already present; overwriting...")