Remove: logically dead code from font cache

The outer if statement checks for 'aa' being false, so within the inner
statements anything checking aa will have a known result and the other
branch from there will be dead code.

src/fontcache.cpp

@@ -618,9 +618,9 @@ const Sprite *FreeTypeFontCache::InternalGetGlyph(GlyphID key, bool aa)
 	if (this->fs == FS_NORMAL && !aa) {
 		for (uint y = 0; y < (uint)slot->bitmap.rows; y++) {
 			for (uint x = 0; x < (uint)slot->bitmap.width; x++) {
-				if (aa ? (slot->bitmap.buffer[x + y * slot->bitmap.pitch] > 0) : HasBit(slot->bitmap.buffer[(x / 8) + y * slot->bitmap.pitch], 7 - (x % 8))) {
+				if (HasBit(slot->bitmap.buffer[(x / 8) + y * slot->bitmap.pitch], 7 - (x % 8))) {
 					sprite.data[1 + x + (1 + y) * sprite.width].m = SHADOW_COLOUR;
-					sprite.data[1 + x + (1 + y) * sprite.width].a = aa ? slot->bitmap.buffer[x + y * slot->bitmap.pitch] : 0xFF;
+					sprite.data[1 + x + (1 + y) * sprite.width].a = 0xFF;
 				}
 			}
 		}