Move changelog entry from 0.19.1 to 0.20.0

Author: sahildua2305

doc/source/whatsnew/v0.19.1.txt

@@ -81,6 +81,3 @@ Bug Fixes
 
 - Bug in ``pd.pivot_table`` may raise ``TypeError`` or ``ValueError`` when ``index`` or ``columns``
   is not scalar and ``values`` is not specified (:issue:`14380`)
-- Bug in ``pd.pivot_table`` may raise ``TypeError`` or ``ValueError`` when ``index`` or ``columns``
-  is not scalar and ``values`` is not specified (:issue:`14380`)
-- Bug in ``asfreq``, where frequency wasn't set for empty Series (:issue:`14320`)

doc/source/whatsnew/v0.20.0.txt

@@ -80,3 +80,5 @@ Performance Improvements
 
 Bug Fixes
 ~~~~~~~~~
+
+- Bug in ``asfreq``, where frequency wasn't set for empty Series (:issue:`14320`)