Update git submodules

* Update docs/submodules/sdc.git from branch 'master'
  to 521000b2278eaf9fb1e57533e523014da1900098
  - Fix property name regex
    
    property name should contain only letters, numbers and / or underscores
    
    Change-Id: Ic6b8d627a30f5f157bed1617a8af819b66352136
    Issue-ID: SDC-2243
    Signed-off-by: talio <tali.orenbach@amdocs.com>
    
diff --git a/docs/submodules/sdc.git b/docs/submodules/sdc.git
index 04aecc5..521000b 160000
--- a/docs/submodules/sdc.git
+++ b/docs/submodules/sdc.git
@@ -1 +1 @@
-Subproject commit 04aecc5c84e2b2f4c59ec86850d6bcd25d3bc912
+Subproject commit 521000b2278eaf9fb1e57533e523014da1900098