vidjil.cpp, tests: json output, do not output 'quality' when there is no quality

algo/tests/should-get-tests/stanford-json.should-get

@@ -13,6 +13,9 @@ $ Most abundant window
 $ Affect values are over all the sequence
 1: "affectValues": .[^}]*"start": 1, "stop": 128
 
+$ No quality information here
+0: "quality"
+
 $ Segmentation
 1:"name": "IGHV3-23.05 6/ACCCGGGAGGAACAATAT/9 IGHD6-13.01 0//5 IGHJ4.02"
 

algo/vidjil.cpp

@@ -1356,6 +1356,8 @@ int main (int argc, char **argv)
         json_clone["_coverage_info"] = {repComp.getCoverageInfo()};
         //From KmerMultiSegmenter
         json_clone["seg"] = kseg->toJson();
+
+        if (repComp.getQuality().length())
         json_clone["seg"]["quality"] = {
             {"start", 1},
             {"stop", kseg->getSequence().sequence.length()},