Bump max time in test_method_calls_on_proxy() test
Bump max time in test_method_calls_on_proxy() test

On slower platforms, the overhead of the 240 D-BUS Sleep calls is larger than
the current maximum of 6 seconds. A run on a Panda board sometimes fails with

  ERROR:/build/buildd/glib2.0-2.33.8/./gio/tests/gdbus-threading.c:409:test_method_calls_on_proxy:
  assertion failed (elapsed_msec < 6000): (7365 < 6000)

Bump maximum time to 8 seconds to be more resilient to this.

https://bugzilla.gnome.org/show_bug.cgi?id=682222

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