Removed odd backslash

Author: eddiebergman

autosklearn/estimators.py

@@ -234,7 +234,7 @@ def __init__(
 
             Not all keys returned by scikit-learn are supported yet.
 
-        performance_over_time\_ : pandas.core.frame.DataFrame
+        performance_over_time_ : pandas.core.frame.DataFrame
             A ``DataFrame`` containing the models performance over time data. Can be
             used for plotting directly. Please refer to the example
             :ref:`Train and Test Inputs <sphx_glr_examples_40_advanced_example_pandas_train_test.py>`.