remove pattern from docker image

templates/macros/home.jinja

@@ -166,7 +166,6 @@
               {#- Docker images #}
               {%- call inputs.create_text_input(id, "image", 
                 placeholder="e.g. jupyter/datascience-notebook",
-                pattern="(([A-Za-z0-9][A-Za-z0-9_.\-\/]*)?:?[A-Za-z0-9_.\-]+)?",
                 warning="Please enter a valid docker image, e.g. jupyter/datascience-notebook",
                 persistent_hover=True) %}
                 A public registry docker image starting a single-user notebook server.