Fix JavaScript version of gcj2wgs_exact

[cxcxcxcx]

The test was actually failing: % npm test

[email protected] test /Users/chenxing/eviltransform/javascript node test.js

gcj2wgs_exact test 0: distance5695312.758504871 gcj2wgs_exact test 1: distance12596699.5673844 gcj2wgs_exact test 2: distance14679927.891650176 wgs2gcj 2564103 223 ns/op gcj2wgs 3225806 213 ns/op gcj2wgs_exact 348432 2770 ns/op distance 9090909 11 ns/op

Now the errors are gone.