Update git submodules

* Update docs/submodules/oom/offline-installer.git from branch 'master'
  to c241f2ff2e42f32bfa2d9f3b444b6a7edac8a234
  - Fix repo checkout cmd in build guide

    As there is no 'casablanca' branch 'master' should
    be checked out.

    Change-Id: I9fba8ef0b10d3de3891d0e7612571789dfdc9449
    Issue-ID: OOM-1621
    Signed-off-by: Bartek Grzybowski <b.grzybowski@partner.samsung.com>

diff --git a/docs/submodules/oom/offline-installer.git b/docs/submodules/oom/offline-installer.git
index e9fca5e..c241f2f 160000 (submodule)
--- a/docs/submodules/oom/offline-installer.git
+++ b/docs/submodules/oom/offline-installer.git
@@ -1 +1 @@
-Subproject commit e9fca5ef39ebdc51d4d0f1af175960fb51cd903e
+Subproject commit c241f2ff2e42f32bfa2d9f3b444b6a7edac8a234