fix: fix typo in api healthcheck (#106)

Reviewed-on: docker/freshrss#106

overlay/usr/local/bin/healthcheck

@@ -4,7 +4,7 @@
 set -eo pipefail
 
 if [ "$(gomplate -i '{{ getenv "FRESHRSS_API_ENABLED" "false" | conv.ToBool }}')" = "true" ]; then
-    (php -r "readfile('http://127.0.0.1:8080/api/fever.php');" | grep -q 'api_versionX') || exit 1
+    (php -r "readfile('http://127.0.0.1:8080/api/fever.php');" | grep -q 'api_version') || exit 1
 else
     (php -r "readfile('http://127.0.0.1:8080/i/');" | grep -q 'jsonVars') || exit 1
 fi