configure: restore vs_version variable

inadvertently lost in the final patchset of:
078dff7 configure: remove old visual studio support (<2010)

this prevents an empty CONFIG_VS_VERSION and avoids make failure

Change-Id: I529d52eca59329e2715309efd63d80f0e1fed462

diff --git a/configure b/configure
index dbe910bdbc24fadedd776a05e87a4d35f41c58e8..dbbd81f1904d879526654462d60784f56af966d9 100755 (executable)
--- a/configure
+++ b/configure
@@ -640,6 +640,7 @@ process_toolchain() {
     case "$tgt_cc" in
         vs*) enable_feature msvs
              enable_feature solution
+             vs_version=${tgt_cc##vs}
              VCPROJ_SFX=vcxproj
              gen_vcproj_cmd=${source_path}/build/make/gen_msvs_vcxproj.sh
              enabled werror && gen_vcproj_cmd="${gen_vcproj_cmd} --enable-werror"