I tested further, and when we have this horrible mess in the po files:

msgstr ""
"Pro"
"jec"
"t-I"
"d-V"
"ers"
"ion"
": "
"dig"
"ika"
"m\n"

We have a clean string in the .mo file.

So there is no fear to have of:

"Plural-Forms: nplurals=1; plural=0;\n"
"#-#-#-#-#  digikamimageplugin_raindrop.po (digikamimageplugin_raindrop)  #-#-"
"#-#-#\n"
"X-Generator: KBabel 1.11.4\n"

It will be nicely stored in the mo as:

Plural-Forms: nplurals=1; plural=0;
#-#-#-#-#  digikamimageplugin_raindrop.po (digikamimageplugin_raindrop)  #-#-#-#-#
X-Generator: KBabel 1.11.4

So you can safely remove lines starting and ending with #-#-#-#-#.