Take out an unused line from gdatetime tests
Take out an unused line from gdatetime tests

This line was apparently causing build problems on Win64,
and since the only test involving the t_str variable was
already commented out, lets just take this out altogether.

https://bugzilla.gnome.org/show_bug.cgi?id=696970

tamaskenez/glib,lukasz-skalski/glib,tamaskenez/glib,endlessm/glib,johne53/MB3Glib,tchakabam/glib,ieei/glib,Distrotech/glib,MathieuDuponchelle/glib,mzabaluev/glib,cosimoc/glib,krichter722/glib,mzabaluev/glib,tamaskenez/glib,cosimoc/glib,cosimoc/glib,mzabaluev/glib,johne53/MB3Glib,mzabaluev/glib,johne53/MB3Glib,MathieuDuponchelle/glib,cosimoc/glib,johne53/MB3Glib,ieei/glib,krichter722/glib,cention-sany/glib,tchakabam/glib,gale320/glib,johne53/MB3Glib,cention-sany/glib,endlessm/glib,cosimoc/glib,tamaskenez/glib,endlessm/glib,lukasz-skalski/glib,cention-sany/glib,tchakabam/glib,krichter722/glib,endlessm/glib,mzabaluev/glib,tchakabam/glib,Distrotech/glib,tamaskenez/glib,gale320/glib,krichter722/glib,krichter722/glib,endlessm/glib,johne53/MB3Glib,cention-sany/glib,ieei/glib,MathieuDuponchelle/glib,lukasz-skalski/glib,tchakabam/glib,ieei/glib,lukasz-skalski/glib,gale320/glib,gale320/glib,lukasz-skalski/glib,MathieuDuponchelle/glib,MathieuDuponchelle/glib,gale320/glib,cention-sany/glib,Distrotech/glib,Distrotech/glib,ieei/glib,Distrotech/glib