fix exec to one liner

.gitea/workflows/build.yml

@@ -120,16 +120,7 @@ jobs:
           [Desktop Entry]
           Type=Application
           Name=Slideshow App
-          Exec=sh -c ' \
-            i=0; \
-            while [ $i -lt 30 ]; do \
-              if [ "$(ls -A /media/$USER 2>/dev/null)" ] && ping -c 1 -W 1 8.8.8.8 >/dev/null 2>&1; then \
-                break; \
-              fi; \
-              i=$((i+1)); \
-              sleep 1; \
-            done; \
-            cd /usr/share/slideshowapp && /usr/bin/slideshowapp'
+          Exec=sh -c 'i=0; while [ $i -lt 30 ]; do if [ "$(ls -A /media/$USER 2>/dev/null)" ] && ping -c 1 -W 1 8.8.8.8 >/dev/null 2>&1; then break; fi; i=$((i+1)); sleep 1; done; cd /usr/share/slideshowapp && /usr/bin/slideshowapp'
           Terminal=false
           EOF