Update [app] to [common] in configs.

Change-Id: Ieb81dbcb9ac592227133f3e80adcc032d7232f25
Reviewed-on: https://asterix-gerrit.ics.uci.edu/1557
Reviewed-by: Michael Blow <mblow@apache.org>
Sonar-Qube: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
Tested-by: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
BAD: Jenkins <jenkins@fulliautomatix.ics.uci.edu>
diff --git a/asterixdb/asterix-server/src/main/opt/ansible/README b/asterixdb/asterix-server/src/main/opt/ansible/README
index 32e7999..6f3afc5 100644
--- a/asterixdb/asterix-server/src/main/opt/ansible/README
+++ b/asterixdb/asterix-server/src/main/opt/ansible/README
@@ -29,7 +29,7 @@
    all nodes listed in conf/inventory.
 
 3. Edit the instance configuration file conf/cc.conf when necessary.
-   You can add/update whatever parameters in the [app] and [cc] sections.
+   You can add/update whatever parameters in the [common] and [cc] sections.
 
 4. Edit the inventory file conf/inventory when necessary.
    You mostly only need to sepecify the node DNS names (or IPs) for the cluster controller ([cc]) and node controllers
diff --git a/asterixdb/asterix-server/src/main/opt/ansible/conf/cc.conf b/asterixdb/asterix-server/src/main/opt/ansible/conf/cc.conf
index 4887732..e779dc2 100644
--- a/asterixdb/asterix-server/src/main/opt/ansible/conf/cc.conf
+++ b/asterixdb/asterix-server/src/main/opt/ansible/conf/cc.conf
@@ -15,7 +15,7 @@
 ; specific language governing permissions and limitations
 ; under the License.
 
-[app]
+[common]
 log.level=INFO
 
 [nc]