Fix CORS regex

ethsigner/core/src/main/java/tech/pegasys/ethsigner/core/Runner.java

@@ -203,7 +203,7 @@ private String buildCorsRegexFromConfig() {
       return "";
     }
     if (allowedCorsOrigins.contains("*")) {
-      return "*";
+      return ".*.";
     } else {
       final StringJoiner stringJoiner = new StringJoiner("|");
       allowedCorsOrigins.stream().filter(s -> !s.isEmpty()).forEach(stringJoiner::add);