Sleep to force rescheduling main thread during init.

This fixes problems with first context switch data region possibly not being
available for the main thread, if no rescheduling was performed after sys
tracing has started.

client/TracyProfiler.cpp

@@ -1091,6 +1091,7 @@ Profiler::Profiler()
     {
         s_sysTraceThread = (Thread*)tracy_malloc( sizeof( Thread ) );
         new(s_sysTraceThread) Thread( SysTraceWorker, nullptr );
+        std::this_thread::sleep_for( std::chrono::milliseconds( 1 ) );
     }
 #endif