Upgrade mapnik sdk to 691-ga22b3e5

Author: rochoa

package.json

@@ -4,7 +4,7 @@
   "url"           : "http://github.com/mapnik/node-mapnik",
   "homepage"      : "http://mapnik.org",
   "author"        : "Dane Springmeyer <dane@dbsgeo.com> (mapnik.org)",
-  "version"       : "1.4.15-cdb5",
+  "version"       : "1.4.15-cdb6",
   "main"          : "./lib/mapnik.js",
   "binary": {
       "module_name" : "mapnik",

scripts/build_against_sdk.sh

@@ -98,7 +98,7 @@ if [[ "${CXX11:-false}" != false ]]; then
     HASH="1702-g65bd9e6"
 else
     # mapnik 2.3.x / c++11 not enabled
-    HASH="688-g9d40bb2"
+    HASH="691-ga22b3e5"
 fi
 
 if [[ ${platform} == 'linux' ]]; then