fix: handle issue with process and DOM conflict

[IvanKalinin]

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Description of the changes, What, Why and How?

Any DOM element with an id can be accessed from the window object by window.{EL_ID}.
Also, global variables are available without chaining window object. e.g.
variableName // global variable is the same as window.variableName

Therefore if a page contains a DOM element with id "process" the client constructor check typeof process !== "undefined" is not sufficient. process.env.ANY_ENV_VARIABLE will throw the TypeError TypeError: process.env is undefined that crashes the messenger.

Changelog

• Implemented additional check for process.env object.

[oliverlaz]

hi @IvanKalinin, thanks for contributing this fix. It looks good to me.