internal/web3ext: fix method name for enabling mutex profiling (#16964)

internal/web3ext/web3ext.go

@@ -313,8 +313,8 @@ web3._extend({
 			params: 2
 		}),
 		new web3._extend.Method({
-			name: 'setMutexProfileRate',
-			call: 'debug_setMutexProfileRate',
+			name: 'setMutexProfileFraction',
+			call: 'debug_setMutexProfileFraction',
 			params: 1
 		}),
 		new web3._extend.Method({