edit Falco license info so that GitHub recognizes it (#380)

GitHub uses a library called Licensee to identify a project's license
type. It shows this information in the status bar and via the API if it
can unambiguously identify the license.

This commit updates the COPYING file so that it contains only the full
text of the GPL 2.0 license. The info that pertains to OpenSSL has now
been moved to the "License Terms" section in the README.

Collectively, these changes allow Licensee to successfully identify the
license type of Falco as GPL 2.0.

falco-CLA-1.0-signed-off-by: Andrea Kao <eirinikos@gmail.com>

COPYING

@@ -277,18 +277,6 @@ YOU OR THIRD PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER
 PROGRAMS), EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE
 POSSIBILITY OF SUCH DAMAGES.
 
-* In addition, as a special exception, the copyright holders give
-* permission to link the code of portions of this program with the
-* OpenSSL library under certain conditions as described in each
-* individual source file, and distribute linked combinations
-* including the two.
-* You must obey the GNU General Public License in all respects
-* for all of the code used other than OpenSSL.  If you modify
-* file(s) with this exception, you may extend this exception to your
-* version of the file(s), but you are not obligated to do so.  If you
-* do not wish to do so, delete this exception statement from your
-* version.
-
                      END OF TERMS AND CONDITIONS
 
             How to Apply These Terms to Your New Programs

README.md

@@ -41,6 +41,10 @@ License Terms
 ---
 Falco is licensed to you under the [GPL 2.0](./COPYING) open source license.
 
+In addition, as a special exception, the copyright holders give permission to link the code of portions of this program with the OpenSSL library under certain conditions as described in each individual source file, and distribute linked combinations including the two.
+
+You must obey the GNU General Public License in all respects for all of the code used other than OpenSSL.  If you modify file(s) with this exception, you may extend this exception to your version of the file(s), but you are not obligated to do so.  If you do not wish to do so, delete this exception statement from your version.
+
 Contributor License Agreements
 ---
 ### Background