Support GCC 4.7

Removed constructors inheritance.
Removed emplace use.

Change-Id: I45224e3232d39ff22f758c7e387be2c9aff5eae0
Reviewed-on: https://weave-review.googlesource.com/1606
Reviewed-by: Vitaly Buka <vitalybuka@google.com>
diff --git a/src/privet/cloud_delegate.cc b/src/privet/cloud_delegate.cc
index 32ebf48..efb69bd 100644
--- a/src/privet/cloud_delegate.cc
+++ b/src/privet/cloud_delegate.cc
@@ -213,7 +213,7 @@
  private:
   void OnCommandAdded(Command* command) {
     // Set to 0 for any new unknown command.
-    command_owners_.emplace(command->GetID(), 0);
+    command_owners_.insert(std::make_pair(command->GetID(), 0));
   }
 
   void OnCommandRemoved(Command* command) {