Update Pom to remove carbon.mediation.initializer

Change resolve the [ERROR] The projects in the reactor contain a cyclic reference: Edge between 'Vertex{label='org.wso2.carbon:org.wso2.carbon.mediation.ntask:4.3.0-SNAPSHOT'}' and 'Vertex{label='org.wso2.carbon:org.wso2.carbon.mediation.initializer:4.3.0-SNAPSHOT'}' introduces to cycle in the graph org.wso2.carbon:org.wso2.carbon.mediation.initializer:4.3.0-SNAPSHOT --> org.wso2.carbon:org.wso2.carbon.mediation.ntask:4.3.0-SNAPSHOT --> org.wso2.carbon:org.wso2.carbon.mediation.initializer:4.3.0-SNAPSHOT ->