console example: increase main task stack size

Stack size was not sufficient for logging at Verbose log level.

examples/system/console/sdkconfig.defaults

@@ -3,7 +3,7 @@ CONFIG_LOG_BOOTLOADER_LEVEL_WARN=y
 CONFIG_LOG_BOOTLOADER_LEVEL=2
 
 # Increase main task stack size
-CONFIG_MAIN_TASK_STACK_SIZE=6144
+CONFIG_MAIN_TASK_STACK_SIZE=7168
 
 # Enable filesystem
 CONFIG_PARTITION_TABLE_CUSTOM=y