[OMON-634] Drop some initialistaion log messages (#309)

Author: awegrzyn

src/Backends/StdOut.cxx

@@ -44,7 +44,6 @@ inline unsigned long StdOut::convertTimestamp(const std::chrono::time_point<std:
 StdOut::StdOut(const std::string& prefix) : mPrefix(prefix)
 {
   setVerbosity(Verbosity::Debug);
-  MonLogger::Get(Severity::Info) << "StdOut backend initialized" << MonLogger::End();
 }
 
 void StdOut::addGlobalTag(std::string_view name, std::string_view value)

src/Monitoring.cxx

@@ -50,7 +50,6 @@ void Monitoring::enableBuffering(const std::size_t size)
   for (std::underlying_type<Verbosity>::type i = 0; i < static_cast<std::underlying_type<Verbosity>::type>(Verbosity::Debug); i++) {
     mStorage[i].reserve(size);
   }
-  MonLogger::Get() << "Buffering enabled (" << mStorage[0].capacity() << ")" << MonLogger::End();
 }
 
 void Monitoring::flushBuffer()
@@ -93,11 +92,6 @@ void Monitoring::enableProcessMonitoring(const unsigned int interval, std::vecto
     mMonitorRunning = true;
     mMonitorThread = std::thread(&Monitoring::pushLoop, this);
   }
-#ifdef O2_MONITORING_OS_LINUX
-  MonLogger::Get() << "Process Monitor : Automatic updates enabled" << MonLogger::End();
-#else
-  MonLogger::Get() << "Process Monitor : Limited metrics available" << MonLogger::End();
-#endif
 }
 
 void Monitoring::addHostnameTag()