fuzz: Add missing ECC_Start to key_io test

src/test/fuzz/key_io.cpp

@@ -16,7 +16,9 @@
 
 void initialize()
 {
-    SelectParams(CBaseChainParams::REGTEST);
+    static const ECCVerifyHandle verify_handle;
+    ECC_Start();
+    SelectParams(CBaseChainParams::MAIN);
 }
 
 void test_one_input(const std::vector<uint8_t>& buffer)