qi.messaging: Fixes compilation for Boost 1.67.
qi.messaging: Fixes compilation for Boost 1.67.

Change [1] in Boost.Optional 1.66 broke Boost.Range's support for lambdas,
which was then fixed in Boost.Range 1.68 with [2].

[1] https://github.com/boostorg/optional/commit/7541076cf1c95201158e47de10f0c8222fb02a70
[2] https://github.com/boostorg/range/commit/1b4f8100efab5f3b7d9886c3bdfe309b2c500f4e

Change-Id: I86759e247b5dbd335fce73bce59265c4cb641e89
Reviewed-on: http://gerrit2.aldebaran.lan/1346
Reviewed-by: jmonnon <8898eaf233516e520f996a244ca8a12d20f948b1@aldebaran.com>
Reviewed-by: gerrit <3b97070d46ccd66422a8e7b83e6967ed84780538@aldebaran-robotics.com>
Tested-by: gerrit <3b97070d46ccd66422a8e7b83e6967ed84780538@aldebaran-robotics.com>
Reviewed-by: vincent.palancher <f8ff75e1c61314c499fafa8de0d9e004e87e66b0@softbankrobotics.com>
Tested-by: jmonnon <8898eaf233516e520f996a244ca8a12d20f948b1@aldebaran.com>

aldebaran/libqi,aldebaran/libqi,aldebaran/libqi