support for kernel configs without modules support

scripts/build-kernel

@@ -76,17 +76,22 @@ def remove_old_kernels():
 
 def install_kernel():
     makeopts = os.environ.get("MAKEOPTS", "")
+    modules_install = False
 
-    subprocess.check_call(
-        [
-            "make",
-            "-C",
-            "/usr/src/linux",
-            "MAKEOPTS=" + makeopts,
-            "install",
-            "modules_install",
-        ]
-    )
+    for line in open("/usr/src/linux/.config"):
+        if "CONFIG_MODULES=y" in line:
+            modules_install = True
+            break
+
+    if modules_install:
+        subprocess.check_call([
+            'make', '-C', '/usr/src/linux', 'MAKEOPTS=' + makeopts, 'install',
+            'modules_install'
+        ])
+    else:
+        subprocess.check_call([
+            'make', '-C', '/usr/src/linux', 'MAKEOPTS=' + makeopts, 'install'
+        ])
 
     # create the symlink.  /sbin/installkernel claims this is not used on
     # "modern" distributions and doesn't create it (unless it already