configure: fail on --enable-napatech and --disable-shared

Issue: 7165

Plugins can't be build using the standard autoconf/automake
methods. We can get around this by creating our own Makefiles, but
they're often less portable.

For now, fail during ./configure instead of during compile.

configure.ac

@@ -1846,6 +1846,13 @@
                 AS_HELP_STRING([--enable-napatech],[Enabled Napatech Devices]),
                 [ enable_napatech=$enableval ],
                 [ enable_napatech=no])
+    AS_IF([test "x$enable_napatech" = "xyes"], [
+        if test "x$enable_shared" = "xno"; then
+            echo
+            echo "   ERROR! napatech cannot be enabled with --disable-shared"
+            echo
+            exit 1
+        fi
         AC_ARG_ENABLE(napatech_bypass,
                     AS_HELP_STRING([--disable-napatech-bypass],[Disable Bypass feature on Napatech cards]),
                     [ napatech_bypass=$enableval ],
@@ -1900,6 +1907,7 @@
                 echo "Napatech Flow Processing is Disabled."
             fi
         fi
+        ])
 
     if test "x$enable_napatech" = "xyes"; then
         AM_CONDITIONAL([BUILD_NAPATECH], [true])