[horde] Blank configuration tabs

[Jaap Winius]

Quoting Jaap Winius <jwinius at umrk.nl>:

> Recently I installed Debian buster on a new VM and then Horde  
> Groupware 5.2.22 on it, including IMP 6.2.22. I logged in as admin  
> to configure it and everything seemed fine at first, but then I  
> noticed that in the configuration section, for application items  
> where the configuration options are split into tabs, that the tabs  
> are all blank. There seem to be the same number of tabs per  
> application as with my Horde 5.2.17 installation on Debian stretch,  
> but now they all have the same minimum width, no text and clicking  
> on them does nothing.

The only two application configuration items that I use that have  
(blank) tabs are for Horde and for IMP.

I should probably also mention a few errors that show up in the logs  
every time I refresh a configuration page that contains those blank  
tabs:

May 14 23:49:59 chr2 HORDE: [horde] PHP ERROR: Declaration of  
Horde_Form_Type_country::init($prompt = NULL) should be compatible  
with Horde_Form_Type_enum::init($values, $prompt = NULL) [pid 5266 on  
line 0 of "/usr/share/php/Horde/Form/Type.php"]
May 14 23:49:59 chr2 HORDE: [horde] PHP ERROR:  
preg_replace_callback(): Compilation failed: invalid range in  
character class at offset 68 [pid 5266 on line 99 of  
"/usr/share/php/Horde/Text/Filter.php"]

For every time the first of these two errors shows up, it's followed  
by tens of copies of the second one (lots more when the Horde cfg page  
is viewed than the Horde cfg page).

Cheers,

Jaap