Correct the incorrect assumption of detectordotdat file

Although present almost always, according to the control group, the phi
column is the first of the User optional column. So, we can not suppose
it is there.

re #8003

Code/Mantid/Framework/DataHandling/src/ModifyDetectorDotDatFile.cpp

@@ -168,8 +168,10 @@ namespace DataHandling
            continue;
        }
 
-       // First six columns in the file, the detector ID and a code for the type of detector CODE = 3 (psd gas tube)
-       istr >> detID >> offset >> dump >> code >> dump >> dump;
+       // First five columns in the file, the detector ID and a code for the type of detector CODE = 3 (psd gas tube)
+       istr >> detID >> offset >> dump >> code >> dump;
+       if (numColumns > 5)
+         istr >> dump; // get phi
 
        if( code == 3 ){
           // This is detector will look for it in workspace and if found use its position
@@ -187,7 +189,9 @@ namespace DataHandling
               oss.precision(pOffset);
               oss << std::setw(wDet) << detID << std::setw(wOff) << offset;
               oss.precision(pOther);
-              oss << std::setw(wRad) << l2 << std::setw(wCode) << code << std::setw(wAng) << theta << std::setw(wAng) << phi ;
+              oss << std::setw(wRad) << l2 << std::setw(wCode) << code << std::setw(wAng) << theta << std::setw(wAng); 
+              if (numColumns > 5) 
+                oss << phi ; // insert phi
               std::string prefix = oss.str();
               std::string suffix = str.substr( width, std::string::npos );
               out << prefix << suffix << "\n";