Update git submodules

* Update kubernetes/robot from branch 'master'
  to 44a38a594677ca38c4eea288908ebf503ad91b4e
  - Bump 1.6.4 version for Frankfurt maintenance release
    
    This new version includes minor fixes for ue case support
    
    Issue-ID: INT-1652
    
    Signed-off-by: mrichomme <morgan.richomme@orange.com>
    Change-Id: I773d78906c5b32678e58eafe825ba12059ff52cf
    
1 file changed