Add /etc/nsswitch.conf to docker container

Fixes #1269

Dockerfile

@@ -14,10 +14,11 @@
 
 FROM centurylink/ca-certs
 EXPOSE 8000
+ADD contrib/docker/etc/nsswitch.conf /etc/
 
 ENV DATABASE_DRIVER=sqlite3
 ENV DATABASE_CONFIG=/var/lib/drone/drone.sqlite
 
 ADD drone_static /drone_static
 
-ENTRYPOINT ["/drone_static"]
+ENTRYPOINT ["/drone_static"]

contrib/docker/etc/nsswitch.conf

@@ -0,0 +1,19 @@
+# /etc/nsswitch.conf
+#
+# Example configuration of GNU Name Service Switch functionality.
+# If you have the `glibc-doc-reference' and `info' packages installed, try:
+# `info libc "Name Service Switch"' for information about this file.
+
+passwd:         compat
+group:          compat
+shadow:         compat
+
+hosts:          files dns
+networks:       files
+
+protocols:      files
+services:       files
+ethers:         files
+rpc:            files
+
+netgroup:       nis