id3v2 parseMetadata - change search to indexOf

Regex (search) not needed, indexOf will work for a char comparison.
Also will prevent invalid search regex's

Given frameHeader.id = '):=T'

/home/ec2-user/src/node_modules/musicmetadata/lib/id3v2.js:219
        'ABCDEFGHIJKLMNOPQRSTUVWXYZ'.search(frameHeader.id[0]) === -1) {
                                     ^
SyntaxError: Invalid regular expression: /)/: Unmatched ')'
    at new RegExp (<anonymous>)
    at RegExp (<anonymous>)
    at String.search (native)
    at parseMetadata (/home/ec2-user/src/node_modules/musicmetadata/lib/id3v2.js:219:38)
    at /home/ec2-user/src/node_modules/musicmetadata/lib/id3v2.js:38:9
    at emitData (/home/ec2-user/src/node_modules/musicmetadata/node_modules/strtok2/lib/strtok.js:351:20)
    at Stream.dataListener (/home/ec2-user/src/node_modules/musicmetadata/node_modules/strtok2/lib/strtok.js:414:11)
    at Stream.emit (events.js:95:17)
    at Stream.<anonymous> (/home/ec2-user/src/node_modules/musicmetadata/lib/index.js:65:13)
    at Stream.g (events.js:180:16)