generate_secrets: improve portability

Updated print_random function definition to be compatible with multiple default shells

generate_secrets.sh

@@ -1,6 +1,6 @@
 #! /bin/sh
 
-function print_random () {
+print_random () {
   LC_ALL=C tr -dc 'A-Za-z0-9!#%&()*+,-./:;<=>?@[\]^_{|}~' </dev/urandom | head -c 32
 }