style: drop redundant member initializers

- remove constructor member initializers that duplicate the default
  member initialization
- clang-tidy readability-redundant-member-init
  https://clang.llvm.org/extra/clang-tidy/checks/readability/redundant-member-init.html

fairmq/Parts.h

@@ -87,7 +87,7 @@ struct Parts
     const_iterator end() const noexcept { return fParts.end(); }
     const_iterator cend() const noexcept { return fParts.cend(); }
 
-    container fParts{};
+    container fParts;
 };
 
 }   // namespace fair::mq