Qt launcher: spelling fixes

src/GUI/DownloadSettings.qml

@@ -20,7 +20,7 @@ Section {
         id: downloadDir
         label: "Download location"
         description: "FlightGear stores downloaded files (scenery and aircraft) in this location. "
-         + "Depending on your settings, it may grow to a considerable size (many gigabytes)."
+         + "Depending on your settings, it may grow to a considerable size (many gigabytes). "
          + "If you change the download location, files will need to be downloaded again."
         advanced: true
         chooseDirectory: true

src/GUI/RenderSettings.qml

@@ -31,7 +31,7 @@ Section {
         id: msaa
         label: "Anti-aliasing"
         description: "Anti-aliasing improves the appearance of high-contrast edges and lines." +
-        "This is especially noticeable on sloping or diagonal egdes. " +
+            "This is especially noticeable on sloping or diagonal edges. " +
             "Higher settings can reduce performance."
         keywords: ["msaa", "anti", "aliasing", "multi", "sample"]
         choices: ["Off", "2x", "4x"]

src/GUI/ViewSettings.qml

@@ -16,7 +16,7 @@ Section {
         id: windowSize
         enabled: !fullscreen.checked
         label: "Window size"
-        description: "Select the initial size of the window. (This has no effct in full-screen mode)"
+        description: "Select the initial size of the window. (This has no effect in full-screen mode)"
         advanced: true
         choices: ["640x480", "800x600", "1024x768", "1920x1080", "2560x1600" ]
         defaultIndex: 2