Update tutorial_equivariant_graph_embedding.py (#1271)

fix typo

demonstrations/tutorial_equivariant_graph_embedding.py

@@ -24,7 +24,7 @@
 #
 # For example, the graph in the image above is represented by each of the two equivalent adjacency matrices. 
 # The top matrix can be transformed into the bottom matrix 
-# by swapping the first row with the third row, then swapping the third column with the third column, then the  
+# by swapping the first row with the third row, then swapping the third column with the first column, then the  
 # new first row with the second, and finally the first colum with the second.
 #
 # But the number of such permutations grows factorially with the number of nodes in the graph, which