deskutils/nextcloudclient: Fix build failure when tests are enabled

Upstream build system tries to include a Linux only library in the
build when tests are enabled.

This patch has already been accepted upstream.

PR:			258119
Approved by:		Maintiner timeout
Obtained from:		nextcloud/desktop#3880

deskutils/nextcloudclient/Makefile

@@ -29,7 +29,6 @@ CMAKE_ARGS=	-DBUILD_UPDATER:BOOL=OFF \
 		-DWITH_STACK_PROTECTOR:BOOL=OFF
 USE_LDCONFIG=	yes
 
-DEBUG=		yes
 USE_GITHUB=	yes
 GH_ACCOUNT=	nextcloud
 GH_PROJECT=	desktop

deskutils/nextcloudclient/files/patch-test_nextcloud__add__test.cmake

@@ -0,0 +1,11 @@
+--- test/nextcloud_add_test.cmake.orig	2021-09-30 11:13:39 UTC
++++ test/nextcloud_add_test.cmake
+@@ -23,7 +23,7 @@ macro(nextcloud_add_test test_class)
+         )
+     endif()
+
+-    if (UNIX)
++    if (LINUX)
+         target_link_libraries(${OWNCLOUD_TEST_CLASS}Test
+             "${synclib_NAME}_vfs_xattr"
+         )