Don't silently log and continue when changing tor's config fails

We only throw an error when the setconf fails. We should not do that, especially when configuring a bridge.

      let errorObject = {}; 
      if (!this._tlps.TorSetConfWithReply(settingsObject, errorObject)) {
        throw new Error(errorObject.details);                                                                                                                                                                                                                         
      }

An an example, when using provide a bridge with foo bar baz we get the following log messages:

Jul 16 15:55:57.000 [warn] Error parsing Bridge address 'bar'
Jul 16 15:55:57.000 [warn] Controller gave us config lines that didn't validate: Bridge line did not parse. See logs for details.
JavaScript error: resource:///modules/TorProtocolService.jsm, line 128: Error: Unacceptable option value: Bridge line did not parse. See logs for details.

But the user has zero notification about this failure.