Fix inverted blinking speed when fade is enabled

Also make the total time of one blink operation the same
regardless of whether fading is enabled or not.
The slowest blink is 3 seconds for both.

src/trayicon.cpp

@@ -333,10 +333,11 @@ void TrayIcon::enableBlinking(bool enabled)
 
         // If we are using the alpha transition, we have to update icon more often
         if (settings->mBlinkingUseAlphaTransition) {
-            mBlinkingDelta = settings->mBlinkSpeed / 100.0;
-            mBlinkingTimeout = 100;
+            mBlinkingDelta = std::min(1.0, (2.0 / settings->mBlinkSpeed));
+            mBlinkingTimeout = settings->mBlinkSpeed == 1 ? 50 : 100;
         } else {
-            // The blinking speed slider is a value from 0 to 30, so we make it 50x
+            // The blinking speed slider is a value from 0 to 30,
+            // so we make it 50x so the maximum is 1500 ms.
             mBlinkingDelta = 0;
             mBlinkingTimeout = settings->mBlinkSpeed * 50;
         }