update agent.config (#2664)

apm-sniffer/config/agent.config

@@ -31,7 +31,7 @@ agent.service_name=${SW_AGENT_NAME:Your_ApplicationName}
 # Through this config item, skywalking keep your application memory cost estimated.
 # agent.span_limit_per_segment=${SW_AGENT_SPAN_LIMIT:300}
 
-# Ignore the segments if their operation names start with these suffix.
+# Ignore the segments if their operation names end with these suffix.
 # agent.ignore_suffix=${SW_AGENT_IGNORE_SUFFIX:.jpg,.jpeg,.js,.css,.png,.bmp,.gif,.ico,.mp3,.mp4,.html,.svg}
 
 # If true, skywalking agent will save all instrumented classes files in `/debugging` folder.