Fix erroneous reference conversion.

Type '=A1+2', move the cursor over the 'A1', then press Shift-F4. It's
supposed to convert A1 to $A$1, but it changes it to $A$11 instead. This
commit fixes that bug.

Change-Id: Ia41c0617c5a93ad4a153dc4c84cd7db9e2b928f1

sc/source/core/tool/reffind.cxx

@@ -291,7 +291,7 @@ void ScRefFinder::ToggleRel( sal_Int32 nStartPos, sal_Int32 nEndPos )
     OUString aTotal = maFormula.copy(0, nStartPos);
     aTotal += aResult;
     if (nEndPos < maFormula.getLength()-1)
-        aTotal += maFormula.copy(nEndPos);
+        aTotal += maFormula.copy(nEndPos+1);
 
     maFormula = aTotal;
 }