Fixed issues rapid7#7691, silent exit.

Add a print statement to alert user what is missing, user could be confused that "show missing" is empty yet something is missing.

Author: jinq102030

modules/auxiliary/scanner/http/error_sql_injection.rb

@@ -78,12 +78,14 @@ def run_host(ip)
       if not datastore['QUERY'].empty?
         qvars = queryparse(datastore['QUERY']) #Now its a Hash
       else
+        print_error("You need to set QUERY param for GET")
         return
       end
     else
       if not datastore['DATA'].empty?
         qvars = queryparse(datastore['DATA']) #Now its a Hash
       else
+        print_error("You need to set DATA parameter for POST")
         return
       end
     end