Trivial grammatical fix to force cppcheck to run.

Framework/Algorithms/src/GetEi2.cpp

@@ -267,7 +267,7 @@ double GetEi2::calculateEi(const double initial_guess) {
  * passed
  *  @param ws_index :: The workspace index of the detector
  *  @param spectrumInfo :: A spectrum info object for the input workspace
- *  @return The distance between the source and the given detector(or
+ *  @return The distance between the source and the given detector (or
  * DetectorGroup)
  *  @throw runtime_error if there is a problem
  */