Update 2019/endoh/README.md about optimiser

I could have sworn I did this but it doesn't seem to be done, perhaps
because of a merge before I was ready (git stash; git pull .. ; git
stash pop) but this is not clear.

2019/endoh/README.md

@@ -4,6 +4,9 @@
 make
 ```
 
+NOTE: we FORCE disable the optimiser and FORCE enable `-g` as this is a
+BACKTRACE QUINE and NEEDS debugging symbols.
+
 
 ### Bugs and (Mis)features: