Fix unit test for Base91 operations

Update chef.help() test to expect 15 results instead of 13
due to the addition of Base91 operations (ToBase91 and FromBase91)
which are now included when searching for 'base 64'.

Author: ialejandrozalles

tests/node/tests/nodeApi.mjs

@@ -136,7 +136,7 @@ TestRegister.addApiTests([
 
     it("chef.help: returns multiple results", () => {
         const result = chef.help("base 64");
-        assert.strictEqual(result.length, 13);
+        assert.strictEqual(result.length, 15);
     }),
 
     it("chef.help: looks in description for matches too", () => {