fix setting a default font issue in wrong cases
Even if a deleted font is not related to current font,
The download font service changes current font to a default font in some cases.
It is caused by using strncmp without "/" character at end of delete dir path.
ex. Current Font Path - /opt/share/fonts/org.tizen.downloadablefont1/myfont.ttf
Delete Font Path - /opt/share/fonts/org.tizen.downloadablefont
The path for comparing should have "/" at end of the path.
Change-Id: I76bbd3b06a835edb987093f4ee3226c2eb0c01ac