dpkg - triggers looping

[Hajo Locke]

Hello List,

is this the right place to ask general packaging questions? I think i 
need a hint from an experienced deb packager.

Situations is as follows: For my intranet-servers (16.04.2) i do 
packaging of software on my own. I have packaged and installed my own 
php 7.0.14 and now want to upgrade to 7.0.19
creating patches, building etc all was successful. My problem occurs 
when installing package libapache2-mod-php70
I got this message:

Unpacking php70-common (7.0.19-my1) over (7.0.14-my1) ...
Setting up php70-common (7.0.19-my1) ...
dpkg: cycle found while processing triggers:
  chain of packages whose triggers are or may be responsible:
   libapache2-mod-php70 -> libapache2-mod-php70
  packages' pending triggers which are or may be unresolvable:
   libapache2-mod-php70: /etc/php70/conf.d
dpkg: error processing package libapache2-mod-php70 (--configure):
  triggers looping, abandoned
Setting up php70-cli (7.0.19-my1) ...

The problem seems to be located in file /var/lib/dpkg/triggers/File. 
This is triggering line: "/etc/php70/conf.d libapache2-mod-php70" 
inserted by /var/lib/dpkg/info/libapache2-mod-php70.triggers with 
content "interest /etc/php70/conf.d"
I can avoid this by manually editing file /var/lib/dpkg/triggers/File 
before installation and change line "/etc/php70/conf.d 
libapache2-mod-php70"  to "/etc/php7/conf.d libapache2-mod-php70" . yes, 
just 70 to 7 seems to solve the loop.
But what is the problem here? i dont understand why there is a loop and 
how to avoid it generally.  I think i need a helping hand of a pro please.
I tried to fix this line with sed by using the 
libapache2-mod-php70.preinst, but editing or even deletion of this file 
was not successful. no error but also no change.
What should i do now?

Thanks,
Hajo