Update git submodules

* Update docs/submodules/sdc.git from branch 'master'
  to 79ec04301a726e8c48f1275877cb852d2d74adc0
  - Work around potential NullPointerExceptions in HeatTreeManagerUtil
    
    - Replace null return values with empty Map objects
    
    Issue-ID: SDC-2928
    Signed-off-by: Chris Andre <chris.andre@yoppworks.com>
    Change-Id: I3357a8789a00201a7ffda1dbf0be5f08cbb9c33b
    
1 file changed