Remove redundant casts

Change-Id: I858dca60061c3e7a9f60085026c8e45d9b0b35ed
Reviewed-on: http://gerrit.dmdirc.com/3883
Automatic-Compile: DMDirc Build Manager
Reviewed-by: Greg Holmes <greg@dmdirc.com>

src/com/dmdirc/util/collections/DoubleMap.java

 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Map.Entry;
 import java.util.Set;
 
 /**
     @Override
     @SuppressWarnings("unchecked")
     public boolean containsKey(final Object key) {
-        return keys.contains((A) key);
+        return keys.contains(key);
     }
 
     @Override
     @SuppressWarnings("unchecked")
     public boolean containsValue(final Object value) {
-        return values.contains((B) value);
+        return values.contains(value);
     }
 
     @Override