Updating default.xml

Change-Id: I4b27328a6c6300d5c557badba887d2a8ed65f0e0

Author: seL4-ci

default.xml

@@ -31,7 +31,7 @@
   <project name="picotcp.git" path="projects/picotcp" remote="picotcp" revision="13c00a067190f5ec62340ed932a2bb833c366d63" upstream="refs/tags/v1.7.0" dest-branch="refs/tags/v1.7.0"/>
   <project name="polly" path="tools/polly" remote="polly" revision="ef7e79c2c297d456f2742fd0b976f555d058d4e0" upstream="master" dest-branch="master"/>
   <project name="projects_libs.git" path="projects/projects_libs" revision="250ebdc6a1b74ddb12f99eee34c2b41570fe0afa" upstream="master" dest-branch="master"/>
-  <project name="seL4.git" path="kernel" revision="c5b23791ea9f65efc4312c161dd173b7238c5e80" upstream="master" dest-branch="master"/>
+  <project name="seL4.git" path="kernel" revision="d6b4e774ca2e360ba4583094d11cddb1e57b3897" upstream="master" dest-branch="master"/>
   <project name="seL4_libs" path="projects/seL4_libs" revision="88c761538b60a162d008a85642b516ee6707ed7e" upstream="master" dest-branch="master"/>
   <project name="seL4_projects_libs.git" path="projects/seL4_projects_libs" revision="97360824eebc80e9a68fef9ef699f3c0ff8bd792" upstream="master" dest-branch="master"/>
   <project name="seL4_tools.git" path="tools/seL4" revision="bef85f32a4829c5062fd6c808c7cab57b816cd9f" upstream="master" dest-branch="master">