Fix HISTORY.rst typo

Author: DomAyre

src/confcom/HISTORY.rst

@@ -13,10 +13,6 @@ Release History
 ++++++
 * Add a new --enable-stdio flag, with a warning if neither this or --disable-stdio is set
 
-1.2.8
-++++++
-* Add a new --enable-stdio flag, with a warning if neither this or --disable-stdio is set
-
 1.2.7
 ++++++
 * bugfix making it so that oras discover function doesn't error when no fragments are found in the remote repository