Fix string concatenation in initial_prompt

[peilongchencc]

old version:

dialect = "SQL"
initial_prompt = f"You are a {dialect} expert. "
"Please help to generate a SQL query to answer the question. Your response should ONLY be based on the given context and follow the response guidelines and format instructions. "
print(initial_prompt)

terminal ouput:

You are a SQL expert.

new version:

dialect = "SQL"
initial_prompt = f"You are a {dialect} expert. " + \
"Please help to generate a SQL query to answer the question. Your response should ONLY be based on the given context and follow the response guidelines and format instructions. "
print(initial_prompt)

terminal ouput:

You are a SQL expert. Please help to generate a SQL query to answer the question. Your response should ONLY be based on the given context and follow the response guidelines and format instructions.