mxe-activate: fix variable matching

tools/mxe-activate

@@ -11,8 +11,8 @@ MXE_TARGET_LIST=`eval "echo {$MXE_TRIPLETS}.{$MXE_LIB_TYPES}"`
 alias mxe='$MAKE -C $MXE_DIR --no-print-directory'
 
 unset `compgen -e | \
-    grep -vi '^EDITOR=\|^HOME=\|^LANG=\|MXE\|^PATH=' | \
-    grep -vi 'PKG_CONFIG\|PROXY\|^PS1=\|^TERM=' | \
+    grep -vi '^EDITOR\|^HOME\|^LANG\|MXE\|^PATH' | \
+    grep -vi 'PKG_CONFIG\|PROXY\|^PS1\|^TERM' | \
     tr '\n' ' '`
 
 _mxe()