Possible regression in ambiguity reporting

[wasade]

Previously, we only reported ambiguities when they occurred. The output right now seems to always report an ambiguity even if there isn't one.

(qiime2-2019.10) 08:52:08 (dtmcdonald@here):sequence-search@master$ echo "10317.000004216" | redbiom fetch samples --output blhablah.biom --context $ctx
1 sample ambiguities observed. Writing ambiguity mappings to: blhablah.biom.ambiguities
(qiime2-2019.10) 08:55:04 (dtmcdonald@here):sequence-search@master$ biom summarize-table -i blhablah.biom
Num samples: 1
Num observations: 335
Total count: 11,798
Table density (fraction of non-zero values): 1.000

Counts/sample summary:
 Min: 11,798.000
 Max: 11,798.000
 Median: 11,798.000
 Mean: 11,798.000
 Std. dev.: 0.000
 Sample Metadata Categories: None provided
 Observation Metadata Categories: None provided

Counts/sample detail:
10317.000004216.58152: 11,798.000