[RPC] disable import functions in pruned mode

import functions could lead to a rescan beyond prune level

src/wallet/rpcdump.cpp

@@ -95,6 +95,9 @@ Value importprivkey(const Array& params, bool fHelp)
             + HelpExampleRpc("importprivkey", "\"mykey\", \"testing\", false")
         );
 
+    if (fPruneMode)
+        throw JSONRPCError(RPC_WALLET_ERROR, "Importing keys is disabled in pruned mode");
+
     LOCK2(cs_main, pwalletMain->cs_wallet);
 
     EnsureWalletIsUnlocked();
@@ -167,6 +170,9 @@ Value importaddress(const Array& params, bool fHelp)
             + HelpExampleRpc("importaddress", "\"myaddress\", \"testing\", false")
         );
 
+    if (fPruneMode)
+        throw JSONRPCError(RPC_WALLET_ERROR, "Importing addresses is disabled in pruned mode");
+
     LOCK2(cs_main, pwalletMain->cs_wallet);
 
     CScript script;
@@ -237,6 +243,9 @@ Value importwallet(const Array& params, bool fHelp)
             + HelpExampleRpc("importwallet", "\"test\"")
         );
 
+    if (fPruneMode)
+        throw JSONRPCError(RPC_WALLET_ERROR, "Importing wallets is disabled in pruned mode");
+
     LOCK2(cs_main, pwalletMain->cs_wallet);
 
     EnsureWalletIsUnlocked();