[horde] PHP include path problem with Horde on opensuse 42.3

[Admin Beckspaced]

Dear Horde list users,

already posted this on the opensuse list. just thought to also post it 
here to see if someone has some thoughts ;)

I got an openSUSE 42.3 box with PHP 7.0.7 and latest horde 5.2.21 with 
IMP, turba, passwd, etc ...

I installed horde via pear as described in the documents 
https://www.horde.org/apps/horde/docs/INSTALL
and all went smooth and fine.

the only problem I experience is the PHP include path in the php.ini in

/etc/php7/cli/php.ini
/etc/php7/apache/php.ini

the default setting is:

include_path = ".:/usr/share/php7:/usr/share/php7/PEAR"

but this throws a fatal error accessing horde via apache

HORDE: [horde] Error: Class 'PEAR_Config' not found in 
/usr/share/php7/PEAR/Horde/Core/Db/Migration.php:66

if i want to run horde-db-migrate via cli I get the same fatal error

cx20:# horde-db-migrate
PHP Fatal error:  Uncaught Error: Class 'PEAR_Config' not found in 
/usr/bin/horde-db-migrate:28

If I have a look at the php_dir in pear config all seems to look fine

cx20:~ # pear config-show
PEAR directory                 php_dir          /usr/share/php7/PEAR

but I still do get the fatal error!

only if I change the order (move the PEAR path to the front) of the 
include path in the php.ini things do work as they should

include_path = ".:/usr/share/php7/PEAR:/usr/share/php7"

which seems strange to me as PHP should try all the different include 
paths before throwing an error?

anyone here with a similar issue? perhaps someone can shed some light on 
what is going on here?
that would be nice

thanks & greetings
Becki