This patch makes some minor improvements to the meson build system.
The changes are as follows:
* Avoid conditional statements when setting config.h values.
* Ordered calendar dependencies.
* Reused variables derived from options.
* Removed unnecessary new line in the output at the configuration's
end.
* Use set10 function avoiding the trinary operator.
* Removed dependencies on the libgcal dependency, as they are not
needed.
https://bugzilla.gnome.org/show_bug.cgi?id=786481