remove default constructor of CaState

Change-Id: I8d7dbad11299e740bbb94b6f8ebc1bea878e510f
diff --git a/src/ca-module.cpp b/src/ca-module.cpp
index 0c40040..493a959 100644
--- a/src/ca-module.cpp
+++ b/src/ca-module.cpp
@@ -337,7 +337,7 @@
 {
   // get certificate request state
   auto requestState = getCertificateRequest(request);
-  if (requestState== nullptr) {
+  if (requestState == nullptr) {
     NDN_LOG_ERROR("No certificate request state can be found.");
     m_face.put(generateErrorDataPacket(request.getName(), ErrorCode::INVALID_PARAMETER,
                                        "No certificate request state can be found."));