Failing assertion in CSV should remove line breaks to allow using grep

**ankhila imane** ([Bug 62345](https://bz.apache.org/bugzilla//show_bug.cgi?id=62345&redirect=false)):
Hi,

when I created an assertion response with the equals option, than I created the field to register result in csv format, I've got an syntax error in the error message ; it provides additional blank lines and there was missing quotes, which does not respect the normal syntax of csv files.

here is the result :

timeStamp,elapsed,label,responseCode,responseMessage,threadName,dataType,success,failureMessage,bytes,sentBytes,grpThreads,allThreads,Latency,IdleTime,Connect
1525171309281,659,HTTP Request,200,OK,Thread Group 1-1,text,false,"Test failed: code expected to equal /

****** received : [[[200]]]

****** comparison: [[[999]]]

/",12470,121,1,1,658,0,383

regards.

OS: All