[GR-69000] Trivial typo fixed.

PullRequest: graal/21938

Author: wirthi

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/configure/ConfigurationFiles.java

@@ -85,7 +85,7 @@ public static final class Options {
                         AccumulatingLocatableMultiOptionValue.Paths.buildWithCommaDelimiter());
         @Option(help = "Resources describing program elements to be made available for reflection (see ProxyConfigurationFiles).", type = OptionType.User, deprecated = true, //
                         deprecationMessage = "This can be caused by a proxy-config.json file in your META-INF directory. " +
-                                        "Consider including proxy configuration in the reflection section of reachability-metadata.md instead.")//
+                                        "Consider including proxy configuration in the reflection section of reachability-metadata.json instead.")//
         public static final HostedOptionKey<AccumulatingLocatableMultiOptionValue.Strings> DynamicProxyConfigurationResources = new HostedOptionKey<>(
                         AccumulatingLocatableMultiOptionValue.Strings.buildWithCommaDelimiter());