Fix Pylint plugin bug which caused duplicate imports

Signed-off-by: Jean Snyman <git@jsnyman.com>

keylime/models/base/pylint.py

@@ -27,6 +27,9 @@ def register(_linter: "PyLinter") -> None:
     an abstract syntax tree (AST) and iterating through the ``import`` statements contained within. Called by Pylint
     on plugin registration.
     """
+    if base_exports:
+        return
+
     path = os.path.dirname(os.path.realpath(__file__))
     path = os.path.join(path, "__init__.py")