Fix bug in normalize_and_hash_email_address function

[arnau126]

First commit

If email_address has no "@" in it, the function raises IndexError list index out of range in:

is_gmail = re.match(r"^(gmail|googlemail)\.com$", email_parts[1])

because email_parts is a list with only one item.

This PR fix this bug by moving the above line inside the if-block if len(email_parts) > 1 .

Second commit

I've added strip to email_address to honor the Enhanced Conversions doc which says:

[...] In order to standardize the hash results, prior to hashing one of these values you must:

• Remove leading/trailing whitespaces.
• [...]

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[arnau126]

About the second commit, I've just realized that the function calls normalize_and_hash which already does the strip. However I think that we should keep this extra strip in the very beginning of the function so a string like "my.email@gmail.com " (with a trailing whitespace) works.
If we don't perfom this previous strip, the regex won't match, and the period won't be removed.