Remove use of IsInitialBlockDownload in wallet code

This commit does not change behavior.

src/interfaces/chain.h

@@ -178,6 +178,9 @@ public:
     //! Check if p2p enabled.
     virtual bool p2pEnabled() = 0;
 
+    // Check if in IBD.
+    virtual bool isInitialBlockDownload() = 0;
+
     //! Get adjusted time.
     virtual int64_t getAdjustedTime() = 0;