net: pass Span by value to CaptureMessage()

Span is lightweight and need not be passed by const reference.

src/net.cpp

@@ -3087,7 +3087,7 @@ uint64_t CConnman::CalculateKeyedNetGroup(const CAddress& ad) const
 
 void CaptureMessageToFile(const CAddress& addr,
                           const std::string& msg_type,
-                          const Span<const unsigned char>& data,
+                          Span<const unsigned char> data,
                           bool is_incoming)
 {
     // Note: This function captures the message at the time of processing,
@@ -3118,6 +3118,6 @@ void CaptureMessageToFile(const CAddress& addr,
 
 std::function<void(const CAddress& addr,
                    const std::string& msg_type,
-                   const Span<const unsigned char>& data,
+                   Span<const unsigned char> data,
                    bool is_incoming)>
     CaptureMessage = CaptureMessageToFile;

src/net.h

@@ -1275,13 +1275,13 @@ private:
 /** Dump binary message to file, with timestamp */
 void CaptureMessageToFile(const CAddress& addr,
                           const std::string& msg_type,
-                          const Span<const unsigned char>& data,
+                          Span<const unsigned char> data,
                           bool is_incoming);
 
 /** Defaults to `CaptureMessageToFile()`, but can be overridden by unit tests. */
 extern std::function<void(const CAddress& addr,
                           const std::string& msg_type,
-                          const Span<const unsigned char>& data,
+                          Span<const unsigned char> data,
                           bool is_incoming)>
     CaptureMessage;