component/gdal: fix typo with-wepb -> with-webp

configure: WARNING: unrecognized options: --with-wepb

component/gdal/buildout.cfg

@@ -32,7 +32,7 @@ configure-options =
   --with-png=${libpng:location}
   --with-static-proj4=${proj4:location}
   --with-sqlite3=${sqlite3:location}
-  --with-wepb=${webp:location}
+  --with-webp=${webp:location}
   --with-xml2=${libxml2:location}/bin/xml2-config
 environment =
   PATH=${xz-utils:location}/bin:%(PATH)s