Inject additional information to message payloads

This additional information will be used to inject an element inside
messages quoting their parent message.

Bug: twpowertools:153
Change-Id: I502f9f9d0377ad5cb9be9c2a96cec416609e790f
diff --git a/src/models/Gap.js b/src/models/Gap.js
index 131dfbc..59e4882 100644
--- a/src/models/Gap.js
+++ b/src/models/Gap.js
@@ -21,7 +21,7 @@
   }
 
   getStartTimestamp() {
-    const a = this.getStartMicroseconds();
+    let a = this.getStartMicroseconds();
     if (a == null) a = '0';
     return BigInt(a);
   }
@@ -35,7 +35,7 @@
   }
 
   getEndTimestamp() {
-    const a = this.getEndMicroseconds();
+    let a = this.getEndMicroseconds();
     if (a == null) a = '0';
     return BigInt(a);
   }