Update bug_report.md

Simplify the template

.github/ISSUE_TEMPLATE/bug_report.md

@@ -5,19 +5,15 @@ about: Create a report to help us improve
 ---
 
 **Describe the bug (描述bug)**
-A clear and concise description of what the bug is. 请准确描述bug是什么.
 
 **To Reproduce (复现方法)**
-Please describe the steps to reproduce the behavior. 请描述复现问题的步骤.
 
 **Expected behavior (期望行为)**
-A clear and concise description of what you expected to happen. 请准确描述你期望发生什么.
 
 **Versions (各种版本)**
 OS:
 Compiler:
 brpc:
 protobuf:
 
-**Additional context (更多上下文)**
-Add any other context or screenshots here. 这里添加更多上下文或截图.
+**Additional context/screenshots (更多上下文/截图)**