mu-query: remove unnused move ctor

lib/mu-query.cc

@@ -68,8 +68,6 @@ struct Query::Private {
 
 Query::Query(const Store& store) : priv_{std::make_unique<Private>(store)} {}
 
-Query::Query(Query&& other) = default;
-
 Query::~Query() = default;
 
 static Xapian::Enquire&

lib/mu-query.hh

@@ -91,7 +91,6 @@ private:
 	 *
 	 * @param other
 	 */
-	Query(Query&& other);
 
 	struct Private;
 	std::unique_ptr<Private> priv_;