Fix install-protobuf script for macosx install

Signed-off-by: Guillaume Lours <guillaume.lours@docker.com>

scripts/setup/install-protobuf

@@ -37,6 +37,8 @@ amd64|386)
 		wget -O $PROTOBUF_DIR/protobuf "https://github.com/google/protobuf/releases/download/v$PROTOBUF_VERSION/protoc-$PROTOBUF_VERSION-win32.zip"
 	elif [ "$GOOS" = linux ]; then
 		wget -O $PROTOBUF_DIR/protobuf "https://github.com/google/protobuf/releases/download/v$PROTOBUF_VERSION/protoc-$PROTOBUF_VERSION-linux-x86_64.zip"
+    elif [ "$GOOS" = darwin ]; then
+        wget -O $PROTOBUF_DIR/protobuf "https://github.com/google/protobuf/releases/download/v$PROTOBUF_VERSION/protoc-$PROTOBUF_VERSION-osx-x86_64.zip"
 	fi
 	unzip $PROTOBUF_DIR/protobuf -d /usr/local
 	;;

setup-dev.sh

@@ -25,6 +25,6 @@
 # ARISING FROM, OUT OF OR IN CONNECTION WITH
 # THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
 
-./scripts/setup/install-protobufs
+./scripts/setup/install-protobuf
 
 go get github.com/stevvooe/protobuild