Don't load GOST ENGINE if it is already loaded.

Multiple copies of the ENGINE will cause problems when it is cleaned up as
the methods are stored in static structures which will be overwritten and
freed up more than once.

Set static methods to NULL when the ENGINE is freed so it can be reloaded.

engines/ccgost/gost_eng.c

@@ -64,6 +64,13 @@ static int gost_engine_finish(ENGINE *e)
 static int gost_engine_destroy(ENGINE *e)
 	{ 
 	gost_param_free();
+
+	pmeth_GostR3410_94 = NULL;
+	pmeth_GostR3410_2001 = NULL;
+	pmeth_Gost28147_MAC = NULL;
+	ameth_GostR3410_94 = NULL;
+	ameth_GostR3410_2001 = NULL;
+	ameth_Gost28147_MAC = NULL;
 	return 1;
 	}
 
@@ -263,7 +270,10 @@ static ENGINE *engine_gost(void)
 	
 void ENGINE_load_gost(void)
 	{
-	ENGINE *toadd =engine_gost();
+	ENGINE *toadd;
+	if (pmeth_GostR3410_94)
+		return;
+	toadd = engine_gost();
 	if (!toadd) return;
 	ENGINE_add(toadd);
 	ENGINE_free(toadd);