message: Fix a typo in the documentation of Device::Configure().
diff: @@ -115,7 +115,7 @@ private:
  void MarkBackend(Backend::Id b) { backends |= b; }
  public:
  - /// Configure and enable the device backends.
  + /// Configure the Device backends.
  /** The string parameter @a device must be a comma-separated list of backend
  string names (see below). The @a dev argument specifies the ID of the
  actual devices (e.g. GPU) to use.
  