builder: small whitespace fix

Two lines before the first class. Will make auto-format happy;
and David.

plugins/builder/osbuild.py

@@ -46,6 +46,7 @@
 # koji API. It is based on the corresponding OpenAPI specification
 # version '1' and should model it closely.
 
+
 class Repository:
     def __init__(self, baseurl: str, gpgkey: str = None):
         self.baseurl = baseurl