fix typo in comment

tools/spacefix.py

@@ -43,7 +43,7 @@ for root, dirs, files in os.walk(mcl5_dir):
                 else:
                     codelist.append("\n"+line_original)
 
-            del codelist[-1] #the last line is there twice, deleting it one...
+            del codelist[-1] #the last line is there twice, deleting it once...
             mod.writelines(codelist)
             mod.close()
             print("DONE! check if mcl5 still works!")