Utils: Fix column returned from helper function

The second function overload must also return 1-based column.

Change-Id: I1d3a58c9267e4a8c8a031c72230f963596a7bb2b
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@qt.io>

src/libs/utils/textutils.cpp

@@ -53,7 +53,7 @@ OptionalLineColumn convertPosition(const QTextDocument *document, int pos)
     QTextBlock block = document->findBlock(pos);
 
     if (block.isValid())
-        optional.emplace(block.blockNumber() + 1, pos - block.position());
+        optional.emplace(block.blockNumber() + 1, pos - block.position() + 1);
 
     return optional;
 }