Update git submodules

* Update docs/submodules/externalapi/nbi.git from branch 'master'
  to b9c025acf17c887ee3a98d8f9b2efe316270b60a
  - Merge "Update to Spring Boot 2"
  - Update to Spring Boot 2
    
    -update pom dependencies
    -fix code
    -fix test
    
    Change-Id: I23c3c702c598ce46e5b861a2fbdfd06f2d439c51
    Issue-ID: EXTAPI-192
    Signed-off-by: romaingimbert <romain.gimbert@orange.com>
    
diff --git a/docs/submodules/externalapi/nbi.git b/docs/submodules/externalapi/nbi.git
index 526d2fc..b9c025a 160000
--- a/docs/submodules/externalapi/nbi.git
+++ b/docs/submodules/externalapi/nbi.git
@@ -1 +1 @@
-Subproject commit 526d2fc3562ccafa503ce5d086a7f4da6f2f3393
+Subproject commit b9c025acf17c887ee3a98d8f9b2efe316270b60a