Remove devel package content summary from README

Author: schuhschuh

README.txt

@@ -2,5 +2,3 @@ This package contains a library that implements commandline flags
 processing.  As such it's a replacement for getopt().  It has increased
 flexibility, including built-in support for C++ types like string, and
 the ability to define flags in the source file in which they're used.
-The devel package contains static and debug libraries and header files
-for developing applications that use the gflags package.