Fix exception if init doesnt have a module

Author: lukasmasuch

src/lazydocs/generation.py

@@ -582,7 +582,10 @@ def class2md(self, cls: Any, depth: int = 2) -> str:
 
         try:
             # object module should be the same as the calling module
-            if cls.__init__.__module__ == modname:
+            if (
+                hasattr(cls.__init__, "__module__")
+                and cls.__init__.__module__ == modname
+            ):
                 init = self.func2md(cls.__init__, clsname=clsname)
             else:
                 init = ""