Minor python3 compatible tweaks

Slightly reduces the changes from 2to3 while remaining python2
compatible.
Signed-off-by: NNiels Thykier <niels@thykier.net>

dak/new_security_install.py

@@ -196,7 +196,7 @@ def main():
     else:
         raw_input("Press Enter to continue")
 
-    for acceptfilename in acceptfiles.keys():
+    for acceptfilename in acceptfiles:
         accept_file = open(acceptfilename, "w")
         accept_file.write("OK\n")
         accept_file.close()

daklib/utils.py

@@ -552,13 +552,11 @@ def find_next_free(dest, too_many=100):
 
 
 def result_join(original, sep='\t'):
-    resultlist = []
-    for i in xrange(len(original)):
-        if original[i] is None:
-            resultlist.append("")
-        else:
-            resultlist.append(original[i])
-    return sep.join(resultlist)
+    return sep.join(
+        x if x is not None else ""
+        for x in original
+    )
+
 
 ################################################################################
 
@@ -951,7 +949,7 @@ def parse_wnpp_bug_file(file="/srv/ftp-master.debian.org/scripts/masterfiles/wnp
         if len(splited_line) > 1:
             wnpp[splited_line[0]] = splited_line[1].split("|")
 
-    for source in wnpp.keys():
+    for source in wnpp:
         bugs = []
         for wnpp_bug in wnpp[source]:
             bug_no = re.search(r"(\d)+", wnpp_bug).group()