Change order of variables in appveyor build matrix
Change order of variables in appveyor build matrix

This change no function effect as it changes only order of defined
variables. The only visible change is on appveyor web where variables are
printed in other as they are defined. If list of variables is too long,
variables defined later are hidden on the web interface. Variable
APPVEYOR_BUILD_WORKER_IMAGE was moved to the end of list as it is less
important to know as variable GENERATOR (defines which compiler is used).

dlfcn-win32/dlfcn-win32,dlfcn-win32/dlfcn-win32