removed stray space in '__main__ ' (scikit-learn#8203)

Author: BasilBeirouti

examples/text/document_classification_20newsgroups.py

@@ -85,7 +85,7 @@
 
 
 def is_interactive():
-    return not hasattr(sys.modules['__main__ '], '__file__')
+    return not hasattr(sys.modules['__main__'], '__file__')
 
 # work-around for Jupyter notebook and IPython console
 argv = [] if is_interactive() else sys.argv[1:]