Update git submodules

* Update docs/submodules/externalapi/nbi.git from branch 'master'
  to 7638d1ce560f7dccb15ae5f9900dc12e756a8784
  - Merge "Handle null orchestration-status"
  - Handle null orchestration-status
    
    Change-Id: Iaf0a036c2e49e5b3ac7dcdbd3442adf0b368c21b
    Issue-ID: EXTAPI-224
    Signed-off-by: aosull01 <adrian.osullivan@huawei.com>
    
diff --git a/docs/submodules/externalapi/nbi.git b/docs/submodules/externalapi/nbi.git
index ce6facb..7638d1c 160000
--- a/docs/submodules/externalapi/nbi.git
+++ b/docs/submodules/externalapi/nbi.git
@@ -1 +1 @@
-Subproject commit ce6facb8157453d34fe138c3d48901133a4639e4
+Subproject commit 7638d1ce560f7dccb15ae5f9900dc12e756a8784