Append error number if no message available

"Err:###" instead of just "Err:" in the status bar for default
unspecific message.

Change-Id: Ic1a07e29e1f5eed4ce1ed9300c1f848c7380002e

sc/source/core/data/global.cxx

@@ -454,7 +454,7 @@ OUString ScGlobal::GetLongErrorString(FormulaError nErr)
             pErrNumber = STR_LONG_ERR_NV;
         break;
         default:
-            pErrNumber = STR_ERROR_STR;
+            return ScResId(STR_ERROR_STR) + OUString::number( static_cast<int>(nErr) );
         break;
     }
     return ScResId(pErrNumber);