Update git submodules

* Update docs/submodules/music.git from branch 'master'
  to 787a713e91001278a5258835aaf063cd36335d1b
  - Removed sub-expressions from RestMusicDataAPI

    Fixed critical Sonar issue related to identical sub-expressions
    on both sides of operator.
    Added more details to error logger.

    Change-Id: I421c4ac3894c08b6b174fdaeb6e68be50e024e63
    Issue-ID: MUSIC-328
    Signed-off-by: Robert Bogacki <r.bogacki@samsung.com>

diff --git a/docs/submodules/music.git b/docs/submodules/music.git
index dd89921..787a713 160000 (submodule)
--- a/docs/submodules/music.git
+++ b/docs/submodules/music.git
@@ -1 +1 @@
-Subproject commit dd899213724ceaab3bb141dfb5cbf4eb7b89404a
+Subproject commit 787a713e91001278a5258835aaf063cd36335d1b