Enable Wswitch for OutputType

src/wallet/scriptpubkeyman.cpp

@@ -1900,8 +1900,8 @@ bool DescriptorScriptPubKeyMan::SetupDescriptorGeneration(const CExtKey& master_
         desc_prefix = "wpkh(" + xpub + "/84'";
         break;
     }
-    default: assert(false);
-    }
+    } // no default case, so the compiler can warn about missing cases
+    assert(!desc_prefix.empty());
 
     // Mainnet derives at 0', testnet and regtest derive at 1'
     if (Params().IsTestChain()) {