Introduce an empty "eth_internals.h" file in the plugin sdk to not break compatibility

src_plugin_sdk/src/eth_internals.h

@@ -0,0 +1,21 @@
+/*******************************************************************************
+ *   Ledger Ethereum App
+ *   (c) 2016-2019 Ledger
+ *
+ *  Licensed under the Apache License, Version 2.0 (the "License");
+ *  you may not use this file except in compliance with the License.
+ *  You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ ********************************************************************************/
+
+#pragma once
+
+// Empty file, introduced to not break compatibility following plugin-sdk structure rework
+#warning "Deprecated file, the sdk sources have been rationalized in several dedicated files."