Do not add DESTDIR to recap script on install.

[tonyskapunk]

By this change the functionality of DESTDIR is guaranteed for packaging or troubleshooting purposes only.

It is not expected that recap will work for normal operations when DESTDIR is defined when installing. This is due to the fact that LIBDIR variable inside recap will not make use of DESTDIR value, instead use the value of LIBDIR (from the Makefile or through environment).

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DESTDIR support is commonly used in package creation. It is also helpful to users who want to understand what a given package will install where, and to allow users who don’t normally have permissions to install into protected areas to build and install before gaining those permissions.

[1] https://www.gnu.org/software/make/manual/html_node/DESTDIR.html

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This change keeps the reference of LIBDIR in recap ignoring DESTIDIR:

$ make DESTDIR=/home/tonyskapunk/rpm/BUILDROOT/ PREFIX=/usr install -n | grep LIBDIR
sed -i.orig 's|^\s*\(declare\s\+-r\s\+LIBDIR=\).*$|\1"/usr/lib/recap"|' src/recap

Fix #195

[tonyskapunk]

Merging in development