Update garray_sorted_str.go

bugfix: avoid overflow

container/garray/garray_sorted_str.go

@@ -445,7 +445,7 @@ func (a *SortedStrArray) binSearch(value string, lock bool) (index int, result i
 	mid := 0
 	cmp := -2
 	for min <= max {
-		mid = (min + max) / 2
+		mid = min + int((max-min)/2)
 		cmp = a.getComparator()(value, a.array[mid])
 		switch {
 		case cmp < 0: