spatialite-gis: fix compilation with wxWidgets 3
spatialite-gis: fix compilation with wxWidgets 3

See also https://github.com/Homebrew/homebrew/commit/b31227d6ef602142ea399b04211d306eaaea674c

Closes #298.
Closes #456.

parcollet/homebrew-science,kozo2/homebrew-science,DabeDotCom/homebrew-science,dpo/homebrew-science,goxberry/homebrew-science,heuermh/homebrew-science,quantumsteve/homebrew-science,aeantipov/homebrew-science,pditommaso/homebrew-science,andrewjpage/homebrew-science,ge11232002/homebrew-science,joshbode/homebrew-science,ahundt/homebrew-science,maplesond/homebrew-science,philippbayer/homebrew-science,pmelsted/homebrew-science