Shave off buffer copies in networking code (#11607)

src/network/networkpacket.h

@@ -115,7 +115,8 @@ public:
 	NetworkPacket &operator<<(video::SColor src);
 
 	// Temp, we remove SharedBuffer when migration finished
-	SharedBuffer<u8> oldForgePacket();
+	// ^ this comment has been here for 4 years
+	Buffer<u8> oldForgePacket();
 
 private:
 	void checkReadOffset(u32 from_offset, u32 field_size);