Move logback.xml where the assembly looks for it

The assembly copies logback.xml from src/main/config, but the file sat in
src/main/resources, so that fileSet had been copying nothing and the
config reached the executable jar only as a packaged resource.  It also
reached the library jar, where logback would offer a consumer's own
application this project's logging configuration.

Move it, as S3Proxy has it, and keep a copy under src/test/resources so
that the tests still log the same way.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01M5JVWJN7L3NWmcsYvjeCfc

Author: gaul

src/main/resources/logback.xml src/main/config/logback.xmlsrc/main/resources/logback.xml renamed to src/main/config/logback.xml

@@ -0,0 +1,16 @@
+<configuration>
+  <appender name="STDOUT" class="ch.qos.logback.core.ConsoleAppender">
+    <encoder>
+      <pattern>%.-1p %d{MM-dd HH:mm:ss.SSS} %t %c{30}:%L %X{clientId}|%X{sessionId}:%X{messageId}:%X{fileId}] %m%n</pattern>
+    </encoder>
+    <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
+      <level>${LOG_LEVEL:-info}</level>
+    </filter>
+  </appender>
+
+  <logger name="org.eclipse.jetty" level="${JETTY_LOG_LEVEL:-info}" />
+
+  <root level="${LOG_LEVEL:-info}">
+    <appender-ref ref="STDOUT" />
+  </root>
+</configuration>