appveyor: setting CMake build type has no effect
appveyor: setting CMake build type has no effect

On multi-configuration build systems (such as Visual Studio or NMake), the
build type (aka configuration) is decided at build time whereas on
single-configuration build systems, it is set at configuration time (obviously).

Remove the unnecessary `-DCMAKE_BUILD_TYPE` option from CMake invocation.

Signed-off-by: David Wagner <60228a510f9a76940848fa2d29321fc4edfc2119@intel.com>

miguelgaio/parameter-framework,01org/parameter-framework,01org/parameter-framework,mgaio/parameter-framework,dawagner/parameter-framework,krocard/parameter-framework,01org/parameter-framework,mgaio/parameter-framework,clero/parameter-framework,dawagner/parameter-framework,clero/parameter-framework,dawagner/parameter-framework,krocard/parameter-framework,mgaio/parameter-framework,miguelgaio/parameter-framework,miguelgaio/parameter-framework,clero/parameter-framework,krocard/parameter-framework