Merge pull request #120 from L-j-h-c/fix/#119-emptyMissionToRanking

[Fix] #119 - 미션 리스트가 empty일 경우 랭킹 버튼이 작동하지 않는 오류 수정

SOPT-Stamp-iOS/Projects/Presentation/Sources/MissionListScene/VC/MissionListVC.swift

@@ -312,6 +312,15 @@ extension MissionListVC {
             make.width.equalToSuperview()
             make.bottom.equalToSuperview().priority(.low)
         }
+        bringRankingFloatingButtonToFront()
+    }
+
+    private func bringRankingFloatingButtonToFront() {
+        self.view.subviews.forEach { view in
+            if view == self.rankingFloatingButton {
+                self.view.bringSubviewToFront(rankingFloatingButton)
+            }
+        }
     }
 
     private func applySnapshot(model: [MissionListModel]) {