Fix "1059: error: Mismatched [endsect] near column 9"

Author: igaztanaga

doc/move.qbk

@@ -802,7 +802,7 @@ Special thanks to:
 
 [section:release_notes Release Notes]
 
- [section:release_notes_boost_1_90 Boost 1.90 Release]
+[section:release_notes_boost_1_90 Boost 1.90 Release]
 
 *  Fixed bugs:
    *  [@https://github.com/boostorg/move/issues/61  Git Issue #61: ['"launder_cast triggers warning about dropping const and volatile qualifiers"]].