Revert "Upgrade Travis-ci Linux builds to Qt5.15.2"

This reverts commit 5251c5b.
It doesn't fix #4196 according to feedback in the users forum

travis/linux/after_success.sh

@@ -1,7 +1,7 @@
 #!/bin/bash
 set -ev
-export PATH=/opt/qt515/bin:$PATH
-export LD_LIBRARY_PATH=/opt/qt515/lib/x86_64-linux-gnu:/opt/qt515/lib:$LD_LIBRARY_PATH
+export PATH=/opt/qt514/bin:$PATH
+export LD_LIBRARY_PATH=/opt/qt514/lib/x86_64-linux-gnu:/opt/qt514/lib:$LD_LIBRARY_PATH
 
 ### This script should be run from GoldenCheetah src directory after build
 cd src
@@ -46,10 +46,10 @@ chmod a+x linuxdeployqt-7-x86_64.AppImage
 ./linuxdeployqt-7-x86_64.AppImage appdir/GoldenCheetah -verbose=2 -bundle-non-qt-libs -exclude-libs=libqsqlmysql,libqsqlpsql,libnss3,libnssutil3,libxcb-dri3.so.0 -unsupported-allow-new-glibc
 
 # Add Python and core modules
-wget --no-verbose https://github.com/niess/python-appimage/releases/download/python3.7/python3.7.13-cp37-cp37m-manylinux1_x86_64.AppImage
-chmod +x python3.7.13-cp37-cp37m-manylinux1_x86_64.AppImage
-./python3.7.13-cp37-cp37m-manylinux1_x86_64.AppImage --appimage-extract
-rm -f python3.7.13-cp37-cp37m-manylinux1_x86_64.AppImage
+wget --no-verbose https://github.com/niess/python-appimage/releases/download/python3.7/python3.7.12-cp37-cp37m-manylinux1_x86_64.AppImage
+chmod +x python3.7.12-cp37-cp37m-manylinux1_x86_64.AppImage
+./python3.7.12-cp37-cp37m-manylinux1_x86_64.AppImage --appimage-extract
+rm -f python3.7.12-cp37-cp37m-manylinux1_x86_64.AppImage
 export PATH="$(pwd)/squashfs-root/usr/bin:$PATH"
 pip install --upgrade pip
 pip install -q -r Python/requirements.txt

travis/linux/before_install.sh

@@ -2,11 +2,11 @@
 set -ev
 
 # Add recent Qt dependency ppa, update on a newer qt version.
-sudo add-apt-repository -y ppa:beineri/opt-qt-5.15.2-bionic
+sudo add-apt-repository -y ppa:beineri/opt-qt-5.14.2-bionic
 sudo apt-get update -qq
-sudo apt-get install -qq qt5-default qt515base qt515tools qt515serialport\
- qt515svg qt515multimedia qt515connectivity qt515webengine qt515charts-no-lgpl\
- qt515networkauth-no-lgpl qt515translations
+sudo apt-get install -qq qt5-default qt514base qt514tools qt514serialport\
+ qt514svg qt514multimedia qt514connectivity qt514webengine qt514charts-no-lgpl\
+ qt514networkauth-no-lgpl qt514translations
 
 sudo apt-get install -qq libglu1-mesa-dev
 sudo apt-get install -qq libsamplerate0-dev

travis/linux/before_script.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 set -ev
-export PATH=/opt/qt515/bin:$PATH
+export PATH=/opt/qt514/bin:$PATH
 
 cp qwt/qwtconfig.pri.in qwt/qwtconfig.pri
 cp src/gcconfig.pri.in src/gcconfig.pri

travis/linux/script.sh

@@ -1,6 +1,6 @@
 #!/bin/bash
 set -ev
-export PATH=/opt/qt515/bin:$PATH
+export PATH=/opt/qt514/bin:$PATH
 qmake -recursive QMAKE_CXXFLAGS_WARN_ON+="-Wno-deprecated-declarations -Wno-unused-value" QMAKE_CFLAGS_WARN_ON+="-Wno-deprecated-declarations -Wno-unused-value"
 make -j4
 exit