Replace invalid characters in branch name

The build scripts fail (at least in the Debian version) if the branch name contains the underscore character.
Therefore, the build scripts have been changed such that the underscore character is replaced with a dash. This
change requires the tr utility to be present in the build environment.

buildScripts/buildInstallLocallyApt

@@ -11,7 +11,7 @@ export MAKE_PARALLEL="-j $(nproc)"
 # choose one of the following...
 #
 # export PDF2HTMLEX_BRANCH="<<YourTagHereWithNoSpaces>>"
-export PDF2HTMLEX_BRANCH="$(git rev-parse --abbrev-ref HEAD)"
+export PDF2HTMLEX_BRANCH="$(git rev-parse --abbrev-ref HEAD | tr _ -)"
 
 # The following environment variable determines where the poppler,
 # poppler-data, fontforge and pdf2htmlEX packages are installed.

buildScripts/buildInstallLocallyDnf

@@ -11,7 +11,7 @@ export MAKE_PARALLEL="-j $(nproc)"
 # choose one of the following...
 #
 # export PDF2HTMLEX_BRANCH="<<YourTagHereWithNoSpaces>>"
-export PDF2HTMLEX_BRANCH="$(git rev-parse --abbrev-ref HEAD)"
+export PDF2HTMLEX_BRANCH="$(git rev-parse --abbrev-ref HEAD | tr _ -)"
 
 # The following environment variable determines where the poppler,
 # poppler-data, fontforge and pdf2htmlEX packages are installed.

buildScripts/versionEnvs

@@ -45,7 +45,7 @@ export LINUX_DEPLOY_URL=https://artifacts.assassinate-you.net/artifactory/list/l
 ###################################################################
 
 if [ -z "$PDF2HTMLEX_BRANCH" ]; then
-  export PDF2HTMLEX_BRANCH="$(git rev-parse --abbrev-ref HEAD)"
+  export PDF2HTMLEX_BRANCH="$(git rev-parse --abbrev-ref HEAD | tr _ -)"
   if [ -z "$PDF2HTMLEX_BRANCH" ]; then
     echo ""
     read -p "Enter the pdf2htmlEX branch or version: " PDF2HTMLEX_BRANCH