aedi: fix gmake target build

gmake target wasn't updated after removal of target's directory was introduced

aedi/target/tool_tier1.py

@@ -65,6 +65,10 @@ class GmakeTarget(ConfigureMakeDependencyTarget):
     def __init__(self, name='gmake'):
         super().__init__(name)
 
+        # Target's directory is removed before configuration step
+        # gmake cannot be used to build itself, use system's make instead
+        self.tool = 'make'
+
     def prepare_source(self, state: BuildState):
         state.download_source(
             'https://ftp.gnu.org/gnu/make/make-4.3.tar.lz',