disable weak algorithms

[peppelinux]

The following algorithms must be disabled by default:

• RSA1_5
• none

[peppelinux]

reference
https://tools.ietf.org/html/rfc8725

[rohe]

OK

[peppelinux]

in #38 I found a good compromise

the weak algs doesn't been disabled by default but a warning message raises if there are found in the configuration