Disable tx sig checking at the Application level:

* Only skip sig checking on the RPC/Websocket interface.
* Used by Env tests which submit unsigned transactions.

src/ripple/app/main/Application.cpp

@@ -363,6 +363,8 @@ public:
     boost::asio::signal_set m_signals;
     beast::WaitableEvent m_stop;
 
+    std::atomic<bool> checkSigs_;
+
     std::unique_ptr <ResolverAsio> m_resolver;
 
     io_latency_sampler m_io_latency_sampler;
@@ -490,6 +492,8 @@ public:
 
         , m_signals (get_io_service())
 
+        , checkSigs_(true)
+
         , m_resolver (ResolverAsio::New (get_io_service(), logs_->journal("Resolver")))
 
         , m_io_latency_sampler (m_collectorManager->collector()->make_event ("ios_latency"),
@@ -526,6 +530,8 @@ public:
     void run() override;
     bool isShutdown() override;
     void signalStop() override;
+    bool checkSigs() const override;
+    void checkSigs(bool) override;
 
     //--------------------------------------------------------------------------
 
@@ -1171,6 +1177,16 @@ ApplicationImp::isShutdown()
     return isStopped();
 }
 
+bool ApplicationImp::checkSigs() const
+{
+    return checkSigs_;
+}
+
+void ApplicationImp::checkSigs(bool check)
+{
+    checkSigs_ = check;
+}
+
 //------------------------------------------------------------------------------
 
 void