gradle: desugar retrofuture and remove old deps

Signed-off-by: Jason A. Donenfeld <Jason@zx2c4.com>

1 files changed, 1 insertions, 2 deletions

diff --git a/tunnel/src/main/java/com/wireguard/config/Attribute.java b/tunnel/src/main/java/com/wireguard/config/Attribute.java
index 659f7cf4..447d7216 100644
--- a/tunnel/src/main/java/com/wireguard/config/Attribute.java
+++ b/tunnel/src/main/java/com/wireguard/config/Attribute.java
@@ -8,11 +8,10 @@ package com.wireguard.config;
 import com.wireguard.util.NonNullForAll;
 
 import java.util.Iterator;
+import java.util.Optional;
 import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 
-import java9.util.Optional;
-
 @NonNullForAll
 public final class Attribute {
     private static final Pattern LINE_PATTERN = Pattern.compile("(\\w+)\\s*=\\s*([^\\s#][^#]*)");