take install prefix from the environment

diff --git a/Configure b/Configure
index 810afbd3b40e8a32ec1bd9a6dd8d88975ede36c3..c86189751889631ea67310615a6cdc990a86ccc7 100755 (executable)
--- a/Configure
+++ b/Configure
@@ -623,7 +623,7 @@ my $prefix="";
 my $libdir="";
 my $openssldir="";
 my $exe_ext="";
-my $install_prefix="";
+my $install_prefix= "$ENV{'INSTALL_PREFIX'}";
 my $cross_compile_prefix="";
 my $no_threads=0;
 my $threads=0;