Enable flake8 warning F841 ("local variable 'foo' is assigned to but never used")

contrib/devtools/lint-python.sh

@@ -52,6 +52,7 @@
 # F822 undefined name name in __all__
 # F823 local variable name … referenced before assignment
 # F831 duplicate argument name in function definition
+# F841 local variable 'foo' is assigned to but never used
 # W292 no newline at end of file
 # W504 line break after binary operator
 # W601 .has_key() is deprecated, use "in"
@@ -60,4 +61,4 @@
 # W604 backticks are deprecated, use "repr()"
 # W605 invalid escape sequence "x"
 
-flake8 --ignore=B,C,E,F,I,N,W --select=E112,E113,E115,E116,E125,E131,E133,E223,E224,E271,E272,E273,E274,E275,E304,E306,E502,E702,E703,E714,E721,E741,E742,E743,F401,F402,F404,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F822,F823,F831,W292,W504,W601,W602,W603,W604,W605 .
+flake8 --ignore=B,C,E,F,I,N,W --select=E112,E113,E115,E116,E125,E131,E133,E223,E224,E271,E272,E273,E274,E275,E304,E306,E502,E702,E703,E714,E721,E741,E742,E743,F401,F402,F404,F406,F407,F601,F602,F621,F622,F631,F701,F702,F703,F704,F705,F706,F707,F811,F812,F822,F823,F831,F841,W292,W504,W601,W602,W603,W604,W605 .