Merge pull request #4692 from ros-infrastructure/gazebo_bump

[gazebo] bump version for Gazebo 7 and 9

library/gazebo

@@ -60,12 +60,12 @@ Directory: gazebo/6/ubuntu/trusty/libgazebo6
 
 Tags: gzserver7, gzserver7-xenial
 Architectures: amd64
-GitCommit: 39a6359049303ab233f4050d6d5f0db6fc3d5944
+GitCommit: e8f4c4d8ba96447121ca3b286c965feb0d293689
 Directory: gazebo/7/ubuntu/xenial/gzserver7
 
 Tags: libgazebo7, libgazebo7-xenial
 Architectures: amd64
-GitCommit: 39a6359049303ab233f4050d6d5f0db6fc3d5944
+GitCommit: e8f4c4d8ba96447121ca3b286c965feb0d293689
 Directory: gazebo/7/ubuntu/xenial/libgazebo7
 
 
@@ -94,10 +94,10 @@ Directory: gazebo/8/ubuntu/xenial/libgazebo8
 
 Tags: gzserver9, gzserver9-xenial
 Architectures: amd64
-GitCommit: e89903c18f62ffe10f00dd93c6dc0317b04075d0
+GitCommit: 8639dbf1ee782ea44b7990db3e69781cfabfad1d
 Directory: gazebo/9/ubuntu/xenial/gzserver9
 
 Tags: libgazebo9, libgazebo9-xenial, latest
 Architectures: amd64
-GitCommit: e89903c18f62ffe10f00dd93c6dc0317b04075d0
+GitCommit: 8639dbf1ee782ea44b7990db3e69781cfabfad1d
 Directory: gazebo/9/ubuntu/xenial/libgazebo9