fix(flex-setup): signature verification failed

[manojs1978]

Describe the bug signature verification failed

To Reproduce Steps to reproduce the behavior:

1. add required repos
2. follow steps in https://docs.gluu.org/v5.1.4.nightly/install/vm-install/suse/
3. download and install flex
4. verify rpm file as per given instruction
5. See error

Expected behavior should not get signatre verification

Screenshots If applicable, add screenshots to help explain your problem.

Desktop (please complete the following information):

• OS: suse
• Browser [e.g. chrome, safari]
• Version 15sp5 -flex 5.1.4.nightly -DB opendj Smartphone (please complete the following information):
• Device: [e.g. iPhone6]
• OS: [e.g. iOS8.1]
• Browser [e.g. stock browser, safari]
• Version [e.g. 22]

Additional context Add any other context about the problem here.