Application calling lookup on external-context fails with WFNAM00007: Invalid URL scheme name "null" in JBoss EAP 7

Issue

• We configured an external context in the naming subsystem , but when our application tries to lookup java:global/external/someValue it is failing with WFNAM00007: Invalid URL scheme name "null" in JBoss EAP 7 :

Caused by: javax.naming.InvalidNameException: WFNAM00007: Invalid URL scheme name "null"
    at org.wildfly.naming.client.WildFlyRootContext.getProviderContext(WildFlyRootContext.java:808)
    at org.wildfly.naming.client.WildFlyRootContext.lookup(WildFlyRootContext.java:155)
    at javax.naming.InitialContext.lookup(InitialContext.java:421)
    at javax.naming.InitialContext.lookup(InitialContext.java:421)
    at org.jboss.as.naming.NamingContext.lookup(NamingContext.java:236)
    at org.jboss.as.naming.NamingContext.lookup(NamingContext.java:184)
    at org.jboss.as.naming.InitialContext$DefaultInitialContext.lookup(InitialContext.java:239)
    at org.jboss.as.naming.NamingContext.lookup(NamingContext.java:193)
    at org.jboss.as.naming.NamingContext.lookup(NamingContext.java:189)
    at javax.naming.InitialContext.lookup(InitialContext.java:417)
    at javax.naming.InitialContext.lookup(InitialContext.java:417)
    at org.apache.jsp.context_jsp._jspService(context_jsp.java:114)
    ... 46 more

The external context configuration is :

        <subsystem xmlns="urn:jboss:domain:naming:2.0">
            <bindings>
                <external-context name="java:global/external/" module="org.jboss.as.naming" class="javax.naming.InitialContext" cache="false">
                    <environment>
                        <property name="java.naming.factory.initial" value="org.jboss.naming.remote.client.InitialContextFactory"></property>
                        <property name="java.naming.provider.url" value="http-remoting://remote-host:8080"></property>
                        <property name="java.naming.security.principal" value="user"></property>
                        <property name="java.naming.security.credentials" value="password"></property>
                    </environment>
                </external-context>
            </bindings>
            <remote-naming></remote>
        </subsystem>