core/kmeraffect.h: change AFFECT_AMBIGUOUS constant

AFFECT_AMBIGUOUS character is now '\1', in order to have a different value than AFFECT_UNKNOWN ('\0').

algo/core/kmeraffect.cpp

@@ -131,7 +131,7 @@ KmerAffect KmerAffect::getUnknown() {
 }
 
 bool KmerAffect::isAmbiguous() const {
-  return affect_strand(affect) == 1 && affect_char(affect) == 0;
+  return affect_strand(affect) == 1 && affect_char(affect) == 1;
 }
 
 bool KmerAffect::isUnknown() const {

algo/core/kmeraffect.h

@@ -146,7 +146,7 @@ const KmerAffect AFFECT_UNKNOWN = KmerAffect("", "\0", 0);
 /**
  * Constant defining the ambiguous affectation (many possibilities)
  */
-const KmerAffect AFFECT_AMBIGUOUS = KmerAffect("", "\0", 1); 
+const KmerAffect AFFECT_AMBIGUOUS = KmerAffect("", "\1", 1); 
 
 const KmerAffect AFFECT_V = KmerAffect("", "V", 1); 
 const KmerAffect AFFECT_J = KmerAffect("", "J", 1);