fix loading race condition
fix loading race condition

namespaces like hiccup.page could still be loading in a thread
while another was attempting to use it

thheller/shadow-cljs,thheller/shadow-cljs,thheller/shadow-devtools,thheller/shadow-devtools,thheller/shadow-cljs,thheller/shadow-cljs,thheller/shadow-devtools,thheller/shadow-devtools