Remove newlines from base64 encoded credential

Summary: Some base64 implementations add a new line for compatibility reasons, follys base 64 decode barfs if you do this, so just remove it ourselves

Reviewed By: knekritz

Differential Revision: D61044045

fbshipit-source-id: d8ff3eb5fb885406df32c89cea1c478a30b98dce

fizz/extensions/delegatedcred/Serialization.cpp

@@ -118,10 +118,11 @@ std::unique_ptr<SelfDelegatedCredential> loadDCFromPEM(
   }
   folly::Optional<DelegatedCredential> cred;
   try {
-    auto credData = folly::base64Decode(combinedPemData.substr(
+    auto data = combinedPemData.substr(
         credDataPtr + dcHeader.size(),
-        credDataEndPtr - credDataPtr - dcHeader.size() - 1));
-
+        credDataEndPtr - credDataPtr - dcHeader.size() - 1);
+    data.erase(remove_if(data.begin(), data.end(), ::isspace), data.end());
+    auto credData = folly::base64Decode(data);
     std::vector<Extension> credVec;
     credVec.emplace_back(Extension{
         ExtensionType::delegated_credential,