downgrade to gnupg1 to fix build issue

fholzer · fholzer · commit d582ef345c86 · 2019-03-26T07:50:20.000+01:00
diff --git a/Dockerfile b/Dockerfile
@@ -61,7 +61,7 @@ RUN GPG_KEYS=B0F4253373F8F6F510D42178520A9993A1C052F8 \
 		zlib-dev \
 		linux-headers \
 		curl \
-		gnupg \
+		gnupg1 \
 		libxslt-dev \
 		gd-dev \
 		geoip-dev \
