Fixup .pgmf support (set mode)

The .pgmf file support needed to set the workout mode but
that was missed.

Now tested the Train View with some Tacx ErgoVideos and they
work perfectly.

src/ErgFile.cpp

@@ -136,10 +136,10 @@ void ErgFile::parseTacx()
                     input>>general.brakeCategory;
                     switch (general.wattSlopePulse) {
                     case 0 :
-                        format = ERG;
+                        mode = format = ERG;
                         break;
                     case 1 :
-                        format = CRS;
+                        mode = format = CRS;
                         break;
                     default:
                         happy = false;