prism-auto update: remove use of U mode in open() to avoid deprecation errors.

prism/etc/scripts/prism-auto

@@ -71,12 +71,7 @@ def isWindows():
 
 # compare two files (with filenames f1,f2) for equality
 def compareFiles(f1,f2):
-    # We open the files in 'rU' mode (universal newline mode),
-    # which automatically converts all the different newline
-    # encodings to '\n'.
-    # This allow the two files to differ in their
-    # line ending encodings without affecting equality
-    with open(f1, 'rU') as fp1, open(f2, 'rU') as fp2:
+    with open(f1, 'r') as fp1, open(f2, 'r') as fp2:
         while True:
             s1 = fp1.readline()
             s2 = fp2.readline()