Patch for Ubercart hidden checkout error

Uc_cart version: 6.x-2.15
Drupal version: 6.38

Ubercart hidden checkout error:
No error message appeared when the database connection error occurred.
The drupal user wasn't created and the customer received only one email (below) with the account settings but the username was empty.
The order remained in the state "in checkout".

This uc_cart patch solves the problem. The customer is redirected to
cart/checkout, infornation is written to log and one of these messages appears:

English: "We're sorry. An error occurred while processing your order. Please submit it again."

Czech: "Omlouváme se, při zpracování vaší objednávky došlo k chybě. Odešlete ji prosím znovu."

Sovak: "Ospravedlňujeme sa, pri spracovaní vašej objednávky došlo k chybe. Odošlite ju prosím znova."


The wrong email:
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Subject: Account details for Customer at Site

,

Thank you for registering at Site. You may now log  in to ... using the following username and  password:

username:
password: Password

You may also log in by clicking on this link or copying and pasting it in  your browser:

...

This is a one-time login, so it can be used only once.

After logging in, you will be redirected to ... so you can change your  password.

Site
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