take install prefix from the environment

diff --git a/Configure b/Configure
index 9489bc3742f95fe2cbc5cbec419d8bef35d06969..1d5c46d191b22d52df208ffda5b43aeeb7ede084 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;