How to goto an loop start while in if statement using bash?

What we have:

m=1
while [[ $m -le 5 ]]
do
curl --connect-timeout 5 --max-time 5 -X POST http://ift.tt/2lZZENi >> test.txt
if [ -s test.txt ]
then
    echo "Empty file"
    ##"GO TO BEGIN OF LOOP"##
else
    echo "All fine"
fi

...

done

We'd like to check if test.txt is empty. If it is we need to go to the begin of our loop.

I am new to stackoverflow. Feel free to comment so that I can improve myself in how to ask questions.