msgsm32.acm: Also check for gsm/gsm.h.

Some systems don't have a gsm.h, so try including gsm/gsm.h first
diff --git a/dlls/msgsm32.acm/msgsm32.c b/dlls/msgsm32.acm/msgsm32.c
index 6ad28fb..ad86bc1 100644
--- a/dlls/msgsm32.acm/msgsm32.c
+++ b/dlls/msgsm32.acm/msgsm32.c
@@ -27,7 +27,9 @@
 #include <stdarg.h>
 #include <string.h>
 
-#ifdef HAVE_GSM_H
+#ifdef HAVE_GSM_GSM_H
+#include <gsm/gsm.h>
+#elif defined(HAVE_GSM_H)
 #include <gsm.h>
 #endif