test/py: fix typo in test_efi_loader.py

Make a comment line easier to read.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Signed-off-by: Alexander Graf <agraf@suse.de>
diff --git a/test/py/tests/test_efi_loader.py b/test/py/tests/test_efi_loader.py
index 5d7f5db..4d391e1 100644
--- a/test/py/tests/test_efi_loader.py
+++ b/test/py/tests/test_efi_loader.py
@@ -12,7 +12,7 @@
 
 """
 Note: This test relies on boardenv_* containing configuration values to define
-which the network environment available for testing. Without this, the parts
+which network environment is available for testing. Without this, the parts
 that rely on network will be automatically skipped.
 
 For example: