let's exception not bubble

ensure we can catch  correctly  exceptions based on BaseException.

Note: patch was origninally proposed by the pr #2923, but original
author closed it.

Fix #2923

Author: benoitc

Diff for: gunicorn/workers/base_async.py

@@ -82,7 +82,7 @@ def handle(self, listener, client, addr):
                     self.log.debug("Ignoring socket not connected")
                 else:
                     self.log.debug("Ignoring EPIPE")
-        except Exception as e:
+        except BaseException as e:
             self.handle_error(req, client, addr, e)
         finally:
             util.close(client)

Diff for: gunicorn/workers/sync.py

@@ -154,7 +154,7 @@ def handle(self, listener, client, addr):
                     self.log.debug("Ignoring socket not connected")
                 else:
                     self.log.debug("Ignoring EPIPE")
-        except Exception as e:
+        except BaseException as e:
             self.handle_error(req, client, addr, e)
         finally:
             util.close(client)