htlcswitch/link: revert borking channels on received Errors

Since it turned out borking channels on every received error could cause
us to bork channels in case of a sync error with C-lightning, we revert
this for now.

htlcswitch/link_test.go

@@ -5273,7 +5273,9 @@ func TestChannelLinkFail(t *testing.T) {
 				c.HandleChannelUpdate(err)
 			},
 			false,
-			true,
+			// TODO(halseth) For compatibility with CL we currently
+			// don't treat Errors as permanent errors.
+			false,
 		},
 	}