Ensure exactly one release is selected

Author: chyndman

ElixirWeb.iss

@@ -106,17 +106,19 @@ end;
 procedure PopulatePSelReleaseListBox(StringTable: TStringTable);
 var
   PrereleaseLabel: String;
+  SelectFirst: Boolean;
 begin
   PSelReleaseListBox.Items.Clear;
-
+  SelectFirst := True;
   for i := 0 to GetArrayLength(StringTable) - 1 do begin
     if (StrToInt(StringTable[i][3]) = {#COMPAT_MASK}) then begin
       if StringTable[i][2] = 'true' then begin
         PrereleaseLabel := 'Prerelease';
       end else begin
         PrereleaseLabel := 'Release';
       end;
-      PSelReleaseListBox.AddRadioButton('Elixir version ' + StringTable[i][0], PrereleaseLabel, 0, False, True, StringTable[i]);
+      PSelReleaseListBox.AddRadioButton('Elixir version ' + StringTable[i][0], PrereleaseLabel, 0, SelectFirst, True, StringTable[i]);
+      SelectFirst := False;
     end;
   end;
 end;