Fix a bug in command "Remove Consecutive Duplicate Lines"

...while the last line's prefix is the content of its previous line.

Fix #5462

PowerEditor/src/Notepad_plus.cpp

@@ -1414,7 +1414,7 @@ void Notepad_plus::removeDuplicateLines()
 	_findReplaceDlg.processAll(ProcessReplaceAll, &env, true);
 
 	// remove the last line if it's a duplicate line.
-	env._str2Search = TEXT("^(.+)\\r?\\n(\\1)");
+	env._str2Search = TEXT("^(.+)\\r?\\n(\\1)$");
 	env._str4Replace = TEXT("\\1");
     env._searchType = FindRegex;
 	_findReplaceDlg.processAll(ProcessReplaceAll, &env, true);