Set Apache timeout

The Apache server was killing replication pushes because of a
timeout. The default configuration given in the Ubuntu package
was a timeout of 300 s. In alpine this was not specifically set.

Change-Id: I8f91d187d8f712c8abde8d3797e7c9ac4113f050
diff --git a/container-images/apache-git-http-backend/config/httpd.conf b/container-images/apache-git-http-backend/config/httpd.conf
index dab4881..ce11b35 100644
--- a/container-images/apache-git-http-backend/config/httpd.conf
+++ b/container-images/apache-git-http-backend/config/httpd.conf
@@ -178,6 +178,13 @@
 User ${APACHE_RUN_USER}
 Group ${APACHE_RUN_GROUP}
 
+#
+# Timeout defines, in seconds, the amount of time that the server waits for
+# receipts and transmissions during communications. Timeout is set to 300
+# seconds by default, which is appropriate for most situations.
+#
+Timeout 300
+
 </IfModule>
 
 # 'Main' server configuration