Revert "librrgraph: add array operator"

Author: amin1377

libs/librrgraph/src/base/rr_graph_storage.cpp

@@ -173,10 +173,6 @@ class edge_sort_iterator {
         return &this->swapper_;
     }
 
-    edge_swapper& operator[](ssize_t n) const {
-        return *(*this + n);
-    }
-
     edge_sort_iterator& operator+=(ssize_t n) {
         swapper_.idx_ += n;
         return *this;