Fix wrapsizer min size calculation

Fix the `wxWrapSizer::CalcMinFromMinor` function: at the end of the
calculation a `sumMinor` variable contain minor size sum without minor
size of a last line, so add `maxMinor` size to the result min size.

src/common/wrapsizer.cpp

@@ -465,7 +465,11 @@ void wxWrapSizer::CalcMinFromMinor(int totMinor)
 
         // No spill over?
         if ( !tailSize )
+        {
+            // Add minor size of the last line
+            sumMinor += maxMinor;
             break;
+        }
     }
 
     // Now have min size in the opposite direction