Make qt test compatible with TestChain100Setup framework

Reset global state after rpc tests, and remove unnecessary ECC initialization
to prevent assert error if it is initialized twice.

src/qt/test/rpcnestedtests.cpp

@@ -148,9 +148,13 @@ void RPCNestedTests::rpcNestedTests()
     QVERIFY_EXCEPTION_THROWN(RPCConsole::RPCExecuteCommandLine(result, "rpcNestedTest(abc,,)"), std::runtime_error); //don't tollerate empty arguments when using ,
 #endif
 
+    UnloadBlockIndex();
     delete pcoinsTip;
+    pcoinsTip = nullptr;
     delete pcoinsdbview;
+    pcoinsdbview = nullptr;
     delete pblocktree;
+    pblocktree = nullptr;
 
     boost::filesystem::remove_all(boost::filesystem::path(path));
 }

src/qt/test/test_main.cpp

@@ -7,7 +7,6 @@
 #endif
 
 #include "chainparams.h"
-#include "key.h"
 #include "rpcnestedtests.h"
 #include "util.h"
 #include "uritests.h"
@@ -36,7 +35,6 @@ extern void noui_connect();
 // This is all you need to run all the tests
 int main(int argc, char *argv[])
 {
-    ECC_Start();
     SetupEnvironment();
     SetupNetworking();
     SelectParams(CBaseChainParams::MAIN);
@@ -66,6 +64,5 @@ int main(int argc, char *argv[])
     if (QTest::qExec(&test4) != 0)
         fInvalid = true;
 
-    ECC_Stop();
     return fInvalid;
 }