Update plot_pdb.py

plot_pdb.py

@@ -39,7 +39,7 @@ def get_pdb(sequence):
         if pdb_str == "INTERNAL SERVER ERROR":
             retries += 1
             time.sleep(0.1)
-            pdb = str = None
+            pdb = None #pdb = str = None
 
     #save a pdb format file
     name = sequence[:3] + sequence[-3:]  #combine the firt and last 3 AAs of sequence as a filename.