Non-ASCII code character is found in Ecdh.h

[JonsonTsai1]

Summary:
Non-ASCII code character is found in Ecdh.h file and causing build failure...

Details:
Please check line 9. There are two dash line with different length. The 2nd one is absolutely not an ASCII code.

[aphroteus]

Suggested enhancement

See PR #10347

[gilles-peskine-arm]

We have a script check_files.py that whitelists characters in source files (UnicodeIssueTracker). I think the current list is reasonable for the library sources, but we could be stricter in public headers. From a quick look, the only non-ASCII character that I'd like to keep in public headers is §.