Do not set debug log level when debug flag is used

Unset debug level when --debug is used to not use it as default behavior.
To set debug log level use env variable from CLI help.

dockerfiles/init/modules/che/templates/che.env.erb

@@ -19,7 +19,6 @@ CATALINA_OPTS=-Dcom.sun.management.jmxremote=true -Djava.rmi.server.hostname=loc
 CHE_DEBUG_SERVER=true
 JPDA=jpda
 CHE_ASSEMBLY=<%= scope.lookupvar('che::che_assembly') %>
-CHE_LOG_LEVEL=debug
 JPDA_ADDRESS=<%= scope.lookupvar('che::che_debug_port') %>
 <% if scope.lookupvar('che::che_debug_suspend') == "true" %>JPDA_SUSPEND=y<% end %>
 <% end -%>