Fixed problem if there is only one symbol to read

kernel/modelverse_kernel/compiled.py

@@ -405,10 +405,15 @@ def read_symbols(a, b, **remainder):
     node =      yield [("RD", [obj, "symbols"])]
     keys =      yield [("RDK", [node])]
     keys_v =    yield [("RV", [i]) for i in keys]
+    keys_v = [keys_v] if not isinstance(keys_v, list) else keys_v
     is_in =     yield [("RD", [node, i]) for i in keys_v]
+    is_in = [is_in] if not isinstance(is_in, list) else is_in
     is_in_v =   yield [("RV", [i]) for i in is_in]
+    is_in_v = [is_in_v] if not isinstance(is_in_v, list) else is_in_v
 
     result_v = ["%s:%s\n" % (key, "1" if value else "0") for key, value in zip(keys_v, is_in_v)]
     result_v = "".join(result_v)
     result =    yield [("CNV", [result_v])]
     raise PrimitiveFinished(result)
+
+#TODO fix __read_symbols: breaks test_constructors_al_linkable.py!