ICU-13829 Removes duplicate import statement.

Author: Norbert Runge

icu4j/main/classes/core/src/com/ibm/icu/impl/locale/XLikelySubtags.java

@@ -2,7 +2,6 @@
 // License & terms of use: http://www.unicode.org/copyright.html#License
 package com.ibm.icu.impl.locale;
 
-import java.util.Collection;
 import java.util.Collection;
 import java.util.Collections;
 import java.util.Enumeration;