[OpenID-Specs-eKYC-IDA] Issue #1262: Fix msisdn example (openid/ekyc-ida)

[Vladimir Dzhuvinov]

New issue 1262: Fix msisdn example
https://bitbucket.org/openid/ekyc-ida/issues/1262/fix-msisdn-example

Vladimir Dzhuvinov:

A developer pointed out that the example `msisdn` has an incorrect syntax - the string should be completely numeric, i.e. no leading plus or zero\(s\) in front of the country code. The `msisdn` in the example should therefore appear as \`[1999550123](https://bitbucket.org/openid/ekyc-ida/commits/1999550123)\`.

> msisdn 	string 	End-User's mobile phone number formatted according to ITU-T recommendation \[@!E.164\], e.g., \+1999550123

Thanks,

Vladimir