curl static libs fixes for osx

configure

@@ -99,6 +99,8 @@ if [ ! -z ${LIBCURL_VERSION} ]; then
     CONFIG+="    'curl_static_libs': $(quote_flags $(mason static_libs libcurl ${LIBCURL_VERSION})),"$LN
     CONFIG+="    'curl_cflags': $(quote_flags $(mason cflags libcurl ${LIBCURL_VERSION})),"$LN
     CONFIG+="    'curl_ldflags': $(quote_flags $(mason ldflags libcurl ${LIBCURL_VERSION})),"$LN
+else
+    CONFIG+="    'curl_static_libs': [],"$LN
 fi
 
 if [ ! -z ${GLFW_VERSION} ]; then

linux/mapboxgl-app.gyp

@@ -23,7 +23,6 @@
         '-I<(boost_root)/include',
       ],
       'libraries': [
-        '<@(curl_static_libs)',
         '<@(png_ldflags)',
         '<@(sqlite3_ldflags)',
         '<@(glfw3_static_libs)',