Init ECC context for test_bitcoin_fuzzy.

This avoids calling things like pubkey_parse with a null context argument.

src/test/test_bitcoin_fuzzy.cpp

@@ -18,6 +18,7 @@
 #include "streams.h"
 #include "undo.h"
 #include "version.h"
+#include "pubkey.h"
 
 #include <stdint.h>
 #include <unistd.h>
@@ -60,6 +61,7 @@ bool read_stdin(std::vector<char> &data) {
 
 int main(int argc, char **argv)
 {
+    ECCVerifyHandle globalVerifyHandle;
     std::vector<char> buffer;
     if (!read_stdin(buffer)) return 0;