vendor: update github.com/dropbox/dropbox-sdk-go-unofficial to fix #1806

vendor/github.com/dropbox/dropbox-sdk-go-unofficial/generator/generate-sdk.sh

@@ -15,7 +15,7 @@ stone -v -a :all go_types.stoneg.py "$gen_dir" "$spec_dir"/*.stone
 stone -v -a :all go_client.stoneg.py "$gen_dir" "$spec_dir"/*.stone
 
 # Update SDK and API spec versions
-sdk_version=${1:-"3.0.0"}
+sdk_version=${1:-"4.0.0"}
 pushd ${spec_dir}
 spec_version=$(git rev-parse --short HEAD)
 popd

vendor/github.com/dropbox/dropbox-sdk-go-unofficial/generator/go_client.stoneg.py

@@ -40,7 +40,7 @@ class GoClientBackend(CodeBackend):
             for route in namespace.routes:
                 self._generate_route(namespace, route)
             self.emit('// New returns a Client implementation for this namespace')
-            with self.block('func New(c dropbox.Config) *apiImpl'):
+            with self.block('func New(c dropbox.Config) Client'):
                 self.emit('ctx := apiImpl(dropbox.NewContext(c))')
                 self.emit('return &ctx')
 
@@ -192,7 +192,8 @@ class GoClientBackend(CodeBackend):
             out('err = apiError')
             out('return')
         out('var apiError dropbox.APIError')
-        with self.block('if resp.StatusCode == http.StatusBadRequest'):
+        with self.block("if resp.StatusCode == http.StatusBadRequest || "
+                        "resp.StatusCode == http.StatusInternalServerError"):
             out('apiError.ErrorSummary = string(body)')
             out('err = apiError')
             out('return')