DOC: Minor indentation issue (pandas-dev#24339)

Author: saurav-chakravorty

doc/source/whatsnew/v0.20.0.rst

@@ -1027,7 +1027,7 @@ Retrieving a correlation matrix for a cross-section
 
    df.rolling(12).corr().loc['2016-04-07']
 
-  .. _whatsnew_0200.api_breaking.hdfstore_where:
+.. _whatsnew_0200.api_breaking.hdfstore_where:
 
 HDFStore where string comparison
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^