remove unused PYTHON._PREFIX config variables

These were copy-pasted from the generic Python support in
32466ecc452102a1fc84f4331c0ed099da4e7edc without noticing that they are unused
in the way Python 2 and 3 detection is written. Related to #1992.

diff --git a/configure.ac b/configure.ac
index d653f6c2e8fcac40a09b6f06a5d847aace28c09b..076690592ec13ab4772cfc050948998f642a4bee 100644 (file)
--- a/configure.ac
+++ b/configure.ac
@@ -1309,7 +1309,6 @@ else
                   PYTHON2=
           fi
         fi
-        PYTHON2_PREFIX=`$PYTHON2 -c "import sys; print(sys.prefix)"`
         PYTHON2_INSTALL_DIR="`$PYTHON2 $srcdir/config/config_python.py archsitelib`"
         save_CPPFLAGS=$CPPFLAGS
         CPPFLAGS=$save_CPPFLAGS
@@ -1378,7 +1377,6 @@ else
                   use_python3="No (python-$PYTHON3_VERSION.pc not found)"
           fi
         fi
-        PYTHON3_PREFIX=`$PYTHON3 -c "import sys; print(sys.prefix)"`
         PYTHON3_INSTALL_DIR="`$PYTHON3 $srcdir/config/config_python.py archsitelib`"
         save_CPPFLAGS=$CPPFLAGS
         CPPFLAGS="$CPPFLAGS $PYTHON3_INCLUDES"