Description of problem:

No proper error message shown when there is invalid keysize in override.ini
provided.

[root@master ~]# /usr/sbin/ipa-server-install --hostname=`hostname` -r
TESTRELM.TEST -n testrelm.test -p xxxxxxx -a xxxxxxx -U
--pki-config-override=/root/override.ini
...
....
Done configuring kadmin.
Configuring ipa-custodia
  [1/5]: Making sure custodia container exists
  [2/5]: Generating ipa-custodia config file
  [3/5]: Generating ipa-custodia keys
  [4/5]: starting ipa-custodia
  [5/5]: configuring ipa-custodia to start on boot
Done configuring ipa-custodia.
Configuring certificate server (pki-tomcatd). Estimated time: 3 minutes
  [1/30]: configuring certificate server instance
Failed to configure CA instance: CalledProcessError(Command
['/usr/sbin/pkispawn', '-s', 'CA', '-f', '/tmp/tmp5nix2ehl'] returned non-zero
exit status 1: 'File already exists: /etc/pki/pki-tomcat/server.xml\nFile
already exists: /etc/pki/pki-tomcat/tomcat.conf\nNotice: Trust flag u is set
automatically if the private key is present.\n')
See the installation logs and the following files/directories for more
information:
  /var/log/pki/pki-tomcat
  [error] RuntimeError: CA configuration failed.
CA configuration failed.
The ipa-server-install command failed. See /var/log/ipaserver-install.log for
more information
(failed reverse-i-search)`unisnt': ipa-server-install --^Cinstall -U
[root@master ~]# cat override.ini
[DEFAULT]
ipa_ca_key_size=4094
[root@master ~]#


Version-Release number of selected component (if applicable):
[root@master ~]# rpm -q ipa-server
-- see bugzilla
[root@master ~]#


How reproducible:
Always

Steps to Reproduce:
1. Install IPA with invalid keysize using no proper --pki-config-override

Actual results:
Installation fails with no proper error message

Expected results:
Proper error message should be shown