add fallback for undecodable text in quest disassembler

src/QuestScript.cc

@@ -40,6 +40,7 @@ static TextEncoding encoding_for_language(uint8_t language) {
 
 static string escape_string(const string& data, TextEncoding encoding = TextEncoding::UTF8) {
   string decoded;
+  try {
     switch (encoding) {
       case TextEncoding::UTF8:
         decoded = data;
@@ -59,6 +60,9 @@ static string escape_string(const string& data, TextEncoding encoding = TextEnco
       default:
         return format_data_string(data);
     }
+  } catch (const runtime_error&) {
+    return format_data_string(data);
+  }
 
   string ret = "\"";
   for (char ch : decoded) {