Docker: build without dependencies

Change-Id: Ibbe0ad8cb6817b7c6e77f7991b92f1ad18c13755
diff --git a/Dockerfile b/Dockerfile
index e11cc36..10b4cd7 100644
--- a/Dockerfile
+++ b/Dockerfile
@@ -52,5 +52,5 @@
 ENV DESTDIR /install
 
 RUN cd dhtnet && mkdir build_dev && cd build_dev \
-	&& cmake .. -DCMAKE_INSTALL_PREFIX=/usr \
+	&& cmake .. -DBUILD_DEPENDENCIES=Off -DCMAKE_INSTALL_PREFIX=/usr \
 	&& make -j2 && make install