is a very informal, kind of slang-y shift in pronunciation of .
You'll often see diphthong (two-vowel) portions of words flattened into monophthong (single-vowel) variants in informal speech. Additional examples you might encounter:
* →
* →
* → →
The ending seems to be the most common spelling, but depending on the writer, you might also see (in rough order of frequency) , , or .