In postgresql.conf.sample, use on/off rather than true/false.

We used to be consistent about this, but my recent patch to add a
restart_after_crash GUC failed to follow the existing convention.

Report and patch from Fujii Masao.

Author: robertmhaas

src/backend/utils/misc/postgresql.conf.sample

@@ -524,8 +524,8 @@
 # ERROR HANDLING
 #------------------------------------------------------------------------------
 
-#exit_on_error = false				# terminate session on any error?
-#restart_after_crash = true			# reinitialize after backend crash?
+#exit_on_error = off				# terminate session on any error?
+#restart_after_crash = on			# reinitialize after backend crash?
 
 
 #------------------------------------------------------------------------------