cap escape length in huffman_spectral_data_2

[netliomax25-code]

1. huffman_spectral_data_2 reads the ER/HCR spectral escape with an unbounded length loop, for (i = 4; ; i++), rejected only at i > 32.
2. the standard escape decoder huffman_getescape in the same file caps the length at i < 16 and returns an error for i >= 16, so an over-long escape prefix is accepted here where the standard path rejects it.
3. the wide bound also permits j = off + (1 << i) to shift by up to 32 bits, out of range for the int expression.

Capped the loop at i < 16 and reject i >= 16, matching huffman_getescape. Escapes of length 15 or less, i.e. all well-formed streams, decode unchanged.