Rename variable properly

Dockerfile

@@ -158,7 +158,7 @@ RUN \
     # Create job for waiting for Xvfb to start
     watchStarting="$(mktemp)"; \
     { 2>&1 inotifywait -e create /tmp/.X11-unix/; } | { sed -u -e "/^Watches established.\$/e rm \"$watchStarting\""; } & \
-    resolver="$!"; \
+    displayResolver="$!"; \
     while [ -f "$watchStarting" ]; do true; done; \
     { \
         # Improve arguments for screenshots
@@ -167,7 +167,7 @@ RUN \
     }; \
     displayPID="$!"; \
     # Wait for Xvfb to start
-    wait "$resolver"; \
+    wait "$displayResolver"; \
     /usr/bin/entrypoint wine reg add 'HKLM\Software\Wine\winedbg' /V ShowCrashDialog /T REG_DWORD /D 0; \
     y=0; \
     while ! \