message: fix some JSONS in test
diff: // 9. Prover gets Claims for Proof Request
  completionExpectation = [[ XCTestExpectation alloc] initWithDescription: @"completion finished"];
  - NSString* proofReqJSON = [ NSString stringWithFormat: @"{\
  + NSString* proofReqJSON = [NSString stringWithFormat: @"\
  + {\
  \"nonce\":\"123432421212\",\
  - \"requested_attrs\":{{\"attr1_uuid\":{{\"schema_seq_no\":%d,\"name\":\"name\"}}}},\
  - \"requested_predicates\":{{\"predicate1_uuid\":{{\"attr_name\":\"age\",\"p_type\":\"GE\",\"value\":18}}}}\
  + \"requested_attrs\":{\
  + \"attr1_uuid\":{\
  + \"schema_seq_no\":%d,\
  + \"name\":\"name\"\
  + }\
  + },\
  + \"requested_predicates\":{\
  + \"predicate1_uuid\":{\
  + \"attr_name\":\"age\",\
  + \"p_type\":\"GE\",\
  + \"value\":18\
  + }\
  + }\
  }", seqNo ];
  ret = [SovrinAnoncreds proverGetClaimsForProofReq: walletHandle
  completionExpectation = [[ XCTestExpectation alloc] initWithDescription: @"completion finished"];
  NSString* requestedClaimsJSON = [ NSString stringWithFormat: @"{\
  - \"self_attested_attributes\":{{}},\
  - \"requested_attrs\":{{\"attr1_uuid\":[\"%d\",true]}},\
  - \"requested_predicates\":{{\"predicate1_uuid\":\"%d\"}}\
  + \"self_attested_attributes\":{},\
  + \"requested_attrs\":{\"attr1_uuid\":[\"%d\",true]},\
  + \"requested_predicates\":{\"predicate1_uuid\":\"%d\"}\
  }", seqNo, seqNo ];
  NSString *schemas = [NSString stringWithFormat: @"{\"%d\":%@}", seqNo, schema];
  