replaced findUnique by "default" method in interfaces. (#1124)

src/main/java/io/ebeaninternal/server/expression/DefaultExpressionList.java

@@ -407,11 +407,6 @@ public class DefaultExpressionList<T> implements SpiExpressionList<T> {
     return query.findOneOrEmpty();
   }
 
-  @Override
-  public T findUnique() {
-    return query.findOne();
-  }
-
   @Override
   public ExpressionList<T> filterMany(String prop) {
     return query.filterMany(prop);

src/main/java/io/ebeaninternal/server/expression/FilterExpressionList.java

@@ -81,11 +81,6 @@ public class FilterExpressionList<T> extends DefaultExpressionList<T> {
     return rootQuery.findSet();
   }
 
-  @Override
-  public T findUnique() {
-    return rootQuery.findOne();
-  }
-
   @Override
   public ExpressionList<T> having() {
     throw new PersistenceException(notAllowedMessage);

src/main/java/io/ebeaninternal/server/expression/JunctionExpression.java

@@ -404,11 +404,6 @@ class JunctionExpression<T> implements SpiJunction<T>, SpiExpression, Expression
     return exprList.findOneOrEmpty();
   }
 
-  @Override
-  public T findUnique() {
-    return exprList.findOne();
-  }
-
   @Override
   public Query<T> forUpdate() {
     return exprList.forUpdate();