Error "java.net.BindException: Address already in use" when installing BRMS 6 in EAP domain mode

Issue

I'm trying to install BRMS / BPM Suite 6.x in our Enterprise Application Platform (EAP) domain. On EAP server-group's startup, we have this error in server.log:

Caused by: org.uberfire.java.nio.IOException: java.net.BindException: Address already in use
    at org.uberfire.java.nio.fs.jgit.JGitFileSystemProvider.buildAndStartDaemon(JGitFileSystemProvider.java:473) [uberfire-nio2-jgit-0.3.3-redhat-2.jar:0.3.3-redhat-2]
    at org.uberfire.java.nio.fs.jgit.JGitFileSystemProvider.<init>(JGitFileSystemProvider.java:386) [uberfire-nio2-jgit-0.3.3-redhat-2.jar:0.3.3-redhat-2]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method) [rt.jar:1.7.0_25]
    at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:57) [rt.jar:1.7.0_25]
    at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45) [rt.jar:1.7.0_25]
    at java.lang.reflect.Constructor.newInstance(Constructor.java:526) [rt.jar:1.7.0_25]
    at java.lang.Class.newInstance(Class.java:374) [rt.jar:1.7.0_25]
    at java.util.ServiceLoader$LazyIterator.next(ServiceLoader.java:373) [rt.jar:1.7.0_25]
    ... 81 more
Caused by: java.net.BindException: Address already in use
    at java.net.PlainSocketImpl.socketBind(Native Method) [rt.jar:1.7.0_25]
    at java.net.AbstractPlainSocketImpl.bind(AbstractPlainSocketImpl.java:376) [rt.jar:1.7.0_25]
    at java.net.ServerSocket.bind(ServerSocket.java:376) [rt.jar:1.7.0_25]
    at java.net.ServerSocket.<init>(ServerSocket.java:237) [rt.jar:1.7.0_25]
    at org.uberfire.java.nio.fs.jgit.daemon.git.Daemon.start(Daemon.java:180) [uberfire-nio2-jgit-0.3.3-redhat-2.jar:0.3.3-redhat-2]
    at org.uberfire.java.nio.fs.jgit.JGitFileSystemProvider.buildAndStartDaemon(JGitFileSystemProvider.java:471) [uberfire-nio2-jgit-0.3.3-redhat-2.jar:0.3.3-redhat-2]
    ... 88 more