update CHANGELOG

Author: Christopher Hojny

CHANGELOG

@@ -12,6 +12,7 @@ Fixed bugs
 - disable objective limit during lexicographic dual minimization to keep feasibility status
 - declare infinite bound inference infeasible in SCIPinferVarLbCons() and SCIPinferVarUbCons() to maintain correct loose LP values
 - fixed update of consssorted flags in a variable expressions data when adding an additional constraint using this variable
+- corrected computation of number of variables affected by symmetry
 
 Build system
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