PARTIAL: typofixes (found by misspell_fixer)

Upstream: 9f68ed6b6d1a9c6436ce37913666165f2b180ee3 (PR #6539)

src/qt/splashscreen.cpp

@@ -57,7 +57,7 @@ SplashScreen::SplashScreen(Qt::WindowFlags f, const NetworkStyle *networkStyle)
     QPainter pixPaint(&pixmap);
     pixPaint.setPen(QColor(100,100,100));
 
-    // draw a slighly radial gradient
+    // draw a slightly radial gradient
     QRadialGradient gradient(QPoint(0,0), splashSize.width()/devicePixelRatio);
     gradient.setColorAt(0, Qt::white);
     gradient.setColorAt(1, QColor(247,247,247));