Translations from transifex, fix some strings references

OpenKeychain/src/main/res/values-el/strings.xml

@@ -35,6 +35,8 @@
   <!--errors
          no punctuation, all lowercase,
          they will be put after "error_message", e.g. "Error: file not found"-->
+  <!--errors without preceeding Error:-->
+  <!--results shown after decryption/verification-->
   <!--progress dialogs, usually ending in '…'-->
   <!--action strings-->
   <!--key bit length selections-->