app: copy the value of the unit
app: copy the value of the unit

This should not have any issue, but Go's closures keep suprising me. I
believe it fixes #644. Let's see what Jenkins and Drone think about
that.

hugoantunes/tsuru,gciotta/tsuru,firebitsbr/tsuru,ggarnier/tsuru,hcxiong/tsuru,guilhermebr/tsuru,kgrvamsi/tsuru,mderaldo/tsuru,kgrvamsi/tsuru,hcxiong/tsuru,mderaldo/tsuru,tsuru/tsuru,cezarsa/tsuru,ArxdSilva/tsuru,ggarnier/tsuru,firebitsbr/tsuru,RichardKnop/tsuru,cgvarela/tsuru,RichardKnop/tsuru,gwmoura/tsuru,4eek/tsuru,tsuru/tsuru,cezarsa/tsuru,Endika/tsuru,cezarsa/tsuru,tsuru/tsuru,4eek/tsuru,gwmoura/tsuru,ArxdSilva/tsuru,tuxmonteiro/tsuru,4eek/tsuru,firebitsbr/tsuru,gciotta/tsuru,jblancett/tsuru,Endika/tsuru,gwmoura/tsuru,jblancett/tsuru,Endika/tsuru,ArxdSilva/tsuru,tuxmonteiro/tsuru,guilhermebr/tsuru,cgvarela/tsuru,mderaldo/tsuru,hcxiong/tsuru,ggarnier/tsuru,gciotta/tsuru,RichardKnop/tsuru,cgvarela/tsuru,guilhermebr/tsuru,guilhermebr/tsuru,cezarsa/tsuru,ggarnier/tsuru,kgrvamsi/tsuru,jblancett/tsuru,tsuru/tsuru,hugoantunes/tsuru,tuxmonteiro/tsuru,ArxdSilva/tsuru