qga/main.c: Don't use g_key_file_get/set_int64

qga/main.c: Don't use g_key_file_get/set_int64

These functions don't exist until glib version 2.26. QEMU is currently only
mandating glib 2.12.

This patch replaces the functions with g_key_file_get/set_integer.

Unbreaks the build on Ubuntu 10.04 and RHEL 5.6.

Regression was introduced by 39097daf15c42243742667607d2cad2c9dc4f764

Signed-off-by: Peter Crosthwaite <peter.crosthwaite@xilinx.com>
Message-id: 1363323879-682-1-git-send-email-peter.crosthwaite@xilinx.com
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>