BaseTools/UPT: Fix a install issue

Fix a corner case issue of installing a module without
any files which causes installing UNI file failure

Contributed-under: TianoCore Contribution Agreement 1.0
Signed-off-by: Hess Chen <hesheng.chen@intel.com>
Reviewed-by: Yonghong Zhu <yonghong.zhu@intel.com>

BaseTools/Source/Python/UPT/Library/String.py

@@ -962,7 +962,12 @@ def IsMatchArch(Arch1, Arch2):
 # Return the FileName with index +1 under the FilePath
 #
 def GetUniFileName(FilePath, FileName):
-    Files = os.listdir(FilePath)
+    Files = []
+    try:
+        Files = os.listdir(FilePath)
+    except:
+        pass
+
     LargestIndex = -1
     for File in Files:
         if File.upper().startswith(FileName.upper()) and File.upper().endswith('.UNI'):