Fix serialization options

We use pr-str-safe to serialize 10x's app-db to localstore, protecting
its integrity. Otherwise, 10x crashes at load if the user happens to
set any global vars like *print-length*. Sadly, this crash stays with
them until they clear their localstore.

Our pr-str-safe function misunderstood a naming quirk in clojure
core:
https://github.com/clojure/clojurescript/blob/e7cdc70d0371a26e07e394ea9cd72d5c43e5e363/src/main/cljs/cljs/core.cljs#L186

Fixed it. Now, it actually protects against the issue.

src/day8/re_frame_10x/tools/datafy.cljs

@@ -44,7 +44,6 @@
 
 (defn pr-str-safe [value]
   (pr-str-with-opts [value] {:flush-on-newline true
-                             :print-readably true
-                             :print-meta false
-                             :print-length nil
-                             :print-level nil}))
+                             :readably true
+                             :meta false
+                             :print-length nil}))