Fix code formatting when matching python-template snippets.

Because we were only checking the snippet match for "python" and not "python-template", we were adding { } that are (I suppose) expected for typescript but break python parsing. I've gone with the more general language check here instead of just adding another case in the hopes that it will be more future-proof if we add any more possible keywords.

pxtlib/tutorial.ts

@@ -148,7 +148,7 @@ namespace pxt.tutorial {
                         m2 = "";
                         break;
                 }
-                code.push(m1 == "python" ? `\n${m2}\n` : `{\n${m2}\n}`);
+                code.push(language === "python" ? `\n${m2}\n` : `{\n${m2}\n}`);
                 idx++
                 return "";
             });