Remove static:// prefix from VirtualTargets.DEFAULT

The static:// prefix is not a valid gRPC scheme and causes
IllegalArgumentException when using @ImportGrpcClients without Spring
Boot. Replace the prefix logic with a simple resolution
of "default" to "localhost:9090".

References: gh-401

Signed-off-by: Andrey Litvitski <andrey1010102008@gmail.com>

Author: therepanic

spring-grpc-core/src/main/java/org/springframework/grpc/client/VirtualTargets.java

@@ -16,20 +16,13 @@
 
 package org.springframework.grpc.client;
 
-import java.util.regex.Pattern;
-
 public interface VirtualTargets {
 
-	/** Regex to match the default authority pattern. */
-	Pattern AUTHORITY_PATTERN = Pattern.compile("([^:]+)(?::(\\d+))?");
-
-	/** Default VirtualTargets instance. */
-	VirtualTargets DEFAULT = path -> {
-		if (AUTHORITY_PATTERN.matcher(path).matches()) {
-			return "static://" + path;
-		}
-		return path;
-	};
+	/**
+	 * Default VirtualTargets instance that resolves the logical name "default" to
+	 * "localhost:9090" and returns all other targets as-is.
+	 */
+	VirtualTargets DEFAULT = path -> "default".equals(path) ? "localhost:9090" : path;
 
 	String getTarget(String path);