Fixed IndexOutOfBoundsException when modifying signs on Paper 1.17-1.19

src/main/java/net/coreprotect/paper/Paper_v1_17.java

@@ -8,6 +8,10 @@ public class Paper_v1_17 extends Paper_v1_16 implements PaperInterface {
 
     @Override
     public String getLine(Sign sign, int line) {
+        if (line >= 4) {
+            return "";
+        }
+
         // https://docs.adventure.kyori.net/serializer/
         return LegacyComponentSerializer.legacySection().serialize(sign.line(line));
     }