don't run ThreadMessageHandler at lowered priority

There's no clear reason ThreadMessageHandler should be low priority.
Fixes #8010 (priority inversion).

src/compat.h

@@ -78,17 +78,6 @@ typedef u_int SOCKET;
 #define MSG_NOSIGNAL 0
 #endif
 
-#ifndef WIN32
-// PRIO_MAX is not defined on Solaris
-#ifndef PRIO_MAX
-#define PRIO_MAX 20
-#endif
-#define THREAD_PRIORITY_LOWEST          PRIO_MAX
-#define THREAD_PRIORITY_BELOW_NORMAL    2
-#define THREAD_PRIORITY_NORMAL          0
-#define THREAD_PRIORITY_ABOVE_NORMAL    (-2)
-#endif
-
 #if HAVE_DECL_STRNLEN == 0
 size_t strnlen( const char *start, size_t max_len);
 #endif // HAVE_DECL_STRNLEN

src/net.cpp

@@ -1729,7 +1729,6 @@ void ThreadMessageHandler()
     boost::mutex condition_mutex;
     boost::unique_lock<boost::mutex> lock(condition_mutex);
 
-    SetThreadPriority(THREAD_PRIORITY_BELOW_NORMAL);
     while (true)
     {
         vector<CNode*> vNodesCopy;

src/util.cpp

@@ -790,19 +790,6 @@ bool SetupNetworking()
     return true;
 }
 
-void SetThreadPriority(int nPriority)
-{
-#ifdef WIN32
-    SetThreadPriority(GetCurrentThread(), nPriority);
-#else // WIN32
-#ifdef PRIO_THREAD
-    setpriority(PRIO_THREAD, 0, nPriority);
-#else // PRIO_THREAD
-    setpriority(PRIO_PROCESS, 0, nPriority);
-#endif // PRIO_THREAD
-#endif // WIN32
-}
-
 int GetNumCores()
 {
 #if BOOST_VERSION >= 105600

src/util.h

@@ -208,7 +208,6 @@ std::string HelpMessageOpt(const std::string& option, const std::string& message
  */
 int GetNumCores();
 
-void SetThreadPriority(int nPriority);
 void RenameThread(const char* name);
 
 /**