chore: Make OkHttpClientHelper the first class in the file

`OkHttpClientHelper` should go frist as the file is named after it.

Signed-off-by: Sebastian Schuberth <[email protected]>

utils/ort/src/main/kotlin/OkHttpClientHelper.kt

@@ -55,11 +55,6 @@ import org.ossreviewtoolkit.utils.common.withoutPrefix
 
 typealias BuilderConfiguration = OkHttpClient.Builder.() -> Unit
 
-/**
- * An HTTP-specific download error that enriches an [IOException] with an additional HTTP error code.
- */
-class HttpDownloadError(val code: Int, message: String) : IOException("$message (HTTP code $code)")
-
 /**
  * A helper class to manage OkHttp instances backed by distinct cache directories.
  */
@@ -81,6 +76,11 @@ object OkHttpClientHelper {
         } ?: okHttpClient
 }
 
+/**
+ * An HTTP-specific download error that enriches an [IOException] with an additional HTTP error code.
+ */
+class HttpDownloadError(val code: Int, message: String) : IOException("$message (HTTP code $code)")
+
 private val logger = loggerOf(MethodHandles.lookup().lookupClass())
 
 private const val CACHE_DIRECTORY = "cache/http"