src/owniptc: Moved the “src/libiptc” directory to “src/owniptc” to avoid build issues.

src/owniptc: Moved the “src/libiptc” directory to “src/owniptc” to avoid build issues.

If there is a system-wide version of this library available, the “-I.”
argument (added automatically by automake :() will lead to the shipped
header files being used. Later, the binary is linked with the
system-wide library, which leads to severe problems when API/ABI
incompatibilities have been introduced in other versions.