RemoveAssociation return false when there are two or more association and mime type.

Steps to reproduce:
Create JNLP file with following entry.
   <association extensions="abc" mime-type="x-application/abc"/>
   <association extensions="xyz" mime-type="x-application/xyz"/>

Invoke RemoveAssociation -
        String mime = "x-application/abc";
        String [] exts = {"abc"};
        String mime1 = "x-application/xyz";
        String [] exts1 = {"xyz"};
        boolean result = is.removeAssociation(mime,exts);
        boolean result1 = is.removeAssociation(mime1,exts1);
Expected result and result1 to return true and remove association.

Testcase: http://jdeploy01.india.sun.com:8080/JavawsMustangIntegTest/integrationService/RemoveMultipleAssociation1.jnlp