--fastq_ascii and --fastq_qmax must be no more than 126

[goodcouscous]

https://github.com/torognes/vsearch/blob/e79adfd5c77e4a18c218b5aafa430344127e4a9f/src/vsearch.cc#L4744

what happens to reads with a q20 score when i set fastq_max to 90?

using this command vsearch --fastq_filter file_q20.fastq --fastq_qmax 90 -fastaout file_q20.fasta