main : escape prompt prefix/suffix (#2151)

examples/common.cpp

@@ -418,6 +418,8 @@ bool gpt_params_parse(int argc, char ** argv, gpt_params & params) {
 
     if (escape_prompt) {
         process_escapes(params.prompt);
+        process_escapes(params.input_prefix);
+        process_escapes(params.input_suffix);
     }
 
     return true;