changed severity of G-9040 to blocker

because fuzzy convertions will most probably lead
to an unwanted behaviour, that's a bug

Author: PhilippSalvisberg

docs/4-language-usage/9-function-usage/g-9040.md

@@ -1,6 +1,6 @@
 # G-9040: Try using FX in string to date/time conversion format model to avoid fuzzy conversion.
 
-!!! warning "Major"
+!!! bug "Blocker"
     Reliability, Testability
 
 ## Reason