uvector.h: Add "// namespace rp" at the end of the file.

Fixes a clang-tidy warning:

src/uvector.h:42:1: warning: namespace 'rp' not terminated with a closing comment [google-readability-namespace-comments]
   42 | }
      | ^
      |    // namespace rp
src/uvector.h:11:11: note: namespace 'rp' starts here
   11 | namespace rp {
      |           ^

Author: GerbilSoft

src/uvector.h

@@ -39,4 +39,4 @@ class default_init_allocator : public Alloc
 template<typename T>
 using uvector = std::vector<T, default_init_allocator<T> >;
 
-}
+} // namespace rp