Enable deferred and reuseport (#86)

Configure `deferred` and `reuseport`. nginx will fail if this is configured on multiple server
blocks, so we configure it in a separate server block  instead. As long as it's only set on ONE
server, it works.

`deferred` enables TCP_DEFER_ACCEPT (see the corresponding man pages). This basically allows for
faster connection establishments.

`reuseport` enables SO_REUSEPORT. This has security implications because another process on the
machine can bind to port 80 as well, allowing it to get some connections. However, when only nginx
listens on port 80, every worker process can listen instead of just the master process. This way,
the kernel is able to distribute connections between the worker processes in kernel space instead
of the nginx master process in user space, which should improve performance when many connections
are opened. More info here: https://lwn.net/Articles/542629/

templates/reverse_proxy.conf.j2

@@ -129,3 +129,19 @@ server {
 
 {% endfor %}
 {%- endfor -%}
+
+# Configure `deferred` and `reuseport`. nginx will fail if this is configured on multiple server
+# blocks, so we configure it here instead. As long as it's only set on ONE server, it works.
+#
+# `deferred` enables TCP_DEFER_ACCEPT (see the corresponding man pages). This basically allows for
+# faster connection establishments.
+
+# `reuseport` enables SO_REUSEPORT. This has security implications because another process on the
+# machine can bind to port 80 as well, allowing it to get some connections. However, when only nginx
+# listens on port 80, every worker process can listen instead of just the master process. This way,
+# the kernel is able to distribute connections between the worker processes in kernel space instead
+# of the nginx master process in user space, which should improve performance when many connections
+# are opened. More info here: https://lwn.net/Articles/542629/
+server {
+	listen 443 deferred reuseport ssl;
+}