in Log::~Log(): removed call to save_log_and_clear()

it creates a problem if a buffer is destroyed first:

src/log/log.cpp

@@ -62,14 +62,6 @@ Log::Log()
 
 Log::~Log()
 {
-	// IMPROVE ME
-	// I am not sure if this is a correct behaviour
-	// the log buffer and file logger may not exist now
-	// (life time of objects)
-	// may would be better to have a flag 'clear_at_the_end'
-	// and if true then call this method?
-
-	save_log_and_clear();
 }