nginx: Always use relative paths

So that using non-standard ports, etc. doesn't break things

nginx/generate-config

@@ -17,7 +17,7 @@ LOCATIONS=$(
 		# all services have metrics under /metrics/SERVICE, except for thrimebletrimmer
 		generate_location "/metrics/$name" "http://$name:$port/metrics"
 	done
-	[ -n "$THRIMBLETRIMMER" ] && echo -e "\t\tlocation = / { return 301 \$scheme://\$host/thrimbletrimmer/dashboard.html; }\n\t\tlocation /thrimbletrimmer { }"
+	[ -n "$THRIMBLETRIMMER" ] && echo -e "\t\tlocation = / { return 301 /thrimbletrimmer/dashboard.html; }\n\t\tlocation /thrimbletrimmer { }"
 )
 
 cat > /etc/nginx/nginx.conf <<EOF
@@ -33,6 +33,7 @@ http {
 		listen 80;
 		gzip on;
 		gzip_comp_level 9;
+		absolute_redirect off;
 $LOCATIONS
 	}
 }