gio/tests: Find "true" in PATH opposed to hardcoding the location
gio/tests: Find "true" in PATH opposed to hardcoding the location

Not all systems have /usr/bin/true. Some have it in /bin/true.
Instead of trying to guess a hardcoded path to find it, let
g_app_info_create_from_commandline() internally search PATH
to find the program.

https://bugzilla.gnome.org/show_bug.cgi?id=698655

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