src+tests: make flake8 happy; explicitly mark E722 ignores (bare excepts)

.flake8

@@ -10,9 +10,9 @@ ignore =
     E402,
     # E501: line too long
     E501,
-    # F403: star import used, unable to detect undefined names
-    E741,
     # E741 ambiguous variable name
+    E741,
+    # F403: star import used, unable to detect undefined names
     F403,
     # F405: name may be undefined, or defined from star imports
     F405

src/apps/fido_u2f/__init__.py

@@ -477,7 +477,6 @@ class ConfirmState:
         return await dialog == CONFIRMED
 
 
-
 _state = None  # type: Optional[ConfirmState]  # state for msg_register and msg_authenticate
 _lastreq = None  # type: Optional[Msg]  # last received register/authenticate request
 

src/boot.py

@@ -14,7 +14,7 @@ async def bootscreen():
                 pin = await request_pin()
                 if config.unlock(pin_to_int(pin), show_pin_timeout):
                     return
-        except:
+        except:  # noqa: E722
             pass
 
 

src/trezor/loop.py

@@ -264,7 +264,7 @@ class wait(Syscall):
     def __iter__(self):
         try:
             return (yield self)
-        except:
+        except:  # noqa: E722
             # exception was raised on the waiting task externally with
             # close() or throw(), kill the children tasks and re-raise
             self.exit()

tests/common.py

@@ -1,4 +1,5 @@
 import sys
+
 sys.path.append('../src')
 
 from ubinascii import hexlify, unhexlify

tests/test_trezor.config.py

@@ -82,7 +82,6 @@ class TestConfig(unittest.TestCase):
         self.assertEqual(v1, bytes())
         self.assertEqual(v2, value16)
 
-
     def test_change_pin(self):
         config.init()
         config.wipe()