improve gguf-function-calling parser

Author: okaris

llama_cpp/llama_chat_format.py

@@ -4272,10 +4272,10 @@ def gguf_function_calling(
     initial_gbnf_tool_grammar = (
         f"""
     root ::= message_only | message_with_functions | functions_only
-    message_only ::= "message:" content
-    message_with_functions ::= "message:" content "<function_calls>\\n" functions
+    message_only ::= "message:" anytext
+    message_with_functions ::= "message:" anytext "<function_calls>\\n" functions
     functions_only ::= "<function_calls>\\n" functions
-    content ::= ([^<] | "<" [^f] )+
+    anytext ::= ANYCHAR+
     functions ::= {function_names}
     """
         if tool_choice == "auto"