Firefox breaks beet-js on Linux

[sschiessl-bcp]

firefox 65.0.1

When executing the bitshares_signedmessage example you get the following:

socket.onopen authenticate rejected ReferenceError: "event is not defined"

[sschiessl-bcp]

firefox 66.0

message: "UnknownError The operation failed for reasons unrelated to the database itself and not covered by any other error code."
​name: "OpenFailedError"

[sschiessl-bcp]

Investigations done here
https://github.com/bitshares/beet-js/tree/firefoxfix

[sschiessl-bcp]

firefox 65.0.1

When executing the bitshares_signedmessage example you get the following:

socket.onopen authenticate rejected ReferenceError: "event is not defined"

This is fixed

[sschiessl-bcp]

firefox 66.0

message: "UnknownError The operation failed for reasons unrelated to the database itself and not covered by any other error code."
​name: "OpenFailedError"

This seems to be a bug in firefox, waiting for a fix