Strip out commented-out translations after update

This is necessary because:
- Transifex runs 'msgfmt -c' on any uploaded .po file
- pybabel adds a spurious '#~ msgid ""' to the end of some files
- 'msgfmt -c' ignores that this is commented out, and treats it
  as a syntax error (clashing with the top file definition)

i2p2www/translations/de/LC_MESSAGES/about.po

@@ -2211,15 +2211,3 @@ msgid ""
 "<a href=\"%(future)s\">Future Performance Improvements</a>."
 msgstr ""
 
-#~ msgid "Native IPv6 I2P"
-#~ msgstr ""
-
-#~ msgid ""
-#~ msgstr ""
-
-#~ msgid "Mirrors admin"
-#~ msgstr ""
-
-#~ msgid "manage the project mirrors"
-#~ msgstr ""
-

i2p2www/translations/de/LC_MESSAGES/blog.po

@@ -1861,6 +1861,3 @@ msgstr ""
 msgid "`release signing key`"
 msgstr ""
 
-#~ msgid ""
-#~ msgstr ""
-

i2p2www/translations/de/LC_MESSAGES/docs.po

@@ -17143,6 +17143,3 @@ msgid ""
 "conclusion is not supported by the paper."
 msgstr ""
 
-#~ msgid ""
-#~ msgstr ""
-

i2p2www/translations/de/LC_MESSAGES/get-involved.po

@@ -4092,6 +4092,3 @@ msgid ""
 "href=\"http://%(zzz)s/forums/14\">translation forum on %(zzz)s</a>."
 msgstr ""
 
-#~ msgid ""
-#~ msgstr ""
-

i2p2www/translations/de/LC_MESSAGES/priority.po

@@ -3182,9 +3182,3 @@ msgstr "Foren, Newsseiten, anderes"
 msgid "Very Old Stuff"
 msgstr "Sehr altes Material"
 
-#~ msgid ""
-#~ msgstr ""
-
-#~ msgid "Help channel"
-#~ msgstr "Hilfskanal"
-