Added info about new --log-warnings option.

sql/mysqld.cc

@@ -4523,7 +4523,7 @@ replicating a LOAD DATA INFILE command.",
    0, 0, 0, 0, 0, 0},
   {"version", 'V', "Output version information and exit.", 0, 0, 0, GET_NO_ARG,
    NO_ARG, 0, 0, 0, 0, 0, 0},
-  {"log-warnings", 'W', "Log some not critical warnings to the log file.",
+  {"log-warnings", 'W', "Log some not critical warnings to the log file. Use this option twice, or --log-warnings=2 if you want 'Aborted connections' warning to be logged in the error log file.",
    (gptr*) &global_system_variables.log_warnings,
    (gptr*) &max_system_variables.log_warnings, 0, GET_ULONG, OPT_ARG, 1, 0, 0,
    0, 0, 0},