Mimics PR 1553 against develop (fix)

See diffblue#1553

Author: cesaro

unit/solvers/refinement/string_constraint_instantiation/instantiate_not_contains.cpp

@@ -15,6 +15,7 @@
 #include <langapi/mode.h>
 #include <java_bytecode/java_bytecode_language.h>
 #include <util/simplify_expr.h>
+#include <util/config.h>
 
 /// \class Types used throughout the test. Currently it is impossible to
 /// statically initialize this value, there is a PR to allow this
@@ -146,6 +147,9 @@ SCENARIO("instantiate_not_contains",
   symbol_tablet symtbl;
   const namespacet ns(symtbl);
 
+  // initialize architecture with sensible default values
+  config.set_arch("none");
+
   GIVEN("The not_contains axioms of String.lastIndexOf(String, Int)")
   {
     // Creating strings