Survey: Corrected EOS-M focal length

The 22mm as stated on the lens is actual, not 35mm equvalent as on smaller
cameras.  - So it was wrong to reverse calculate for crop factor.

src/MissionEditor/SurveyItemEditor.qml

@@ -65,7 +65,7 @@ Rectangle {
                sensorHeight:   15.6
                imageWidth:     5184
                imageHeight:    3456
-               focalLength:    14.36
+               focalLength:    22
            }
    }